5.4 Classifying the One Hundred Topics and SubTopics

Now there are one hundred things to be classified: eighty topics and twenty subtopics. The subtopics are individually easier to classify, so that’s nice. On the other hand, I started with a hard task of classifying ninety things, and now I have the hard task of classifying one hundred things, and this doesn’t look like progress.

So it’s time to introduce the tool that I primarily used as a guide to classification. It’s another kind of binary sort, like I used in the last section. Except now instead of applying it to all the articles in one topic, I apply it to all the articles in two categories. The intuition here is that if I’ve really got a good categorization, all the topics/subtopics within each of the categories should cluster together. If the topics/subtopics are not clustering, then that is a reason to be sceptical of the categorization.

Here is a clean example of how it might work. I generated a two topic LDA out of all the articles in the categories ethics and metaphysics. And for each topic, I asked what the average probability was that the article was in topic 1. Remember which topic gets labelled 1 is arbitrary, so this is just asking how close, on average, each of them was to one arbitrarily chosen end of the binary sort.

Table 5.4: Table 5.5: Comparing articles in ethics and metaphysics.
Category	Subject	Mean Probability
Ethics	Forgiveness	0.018
Ethics	Duties	0.031
Ethics	Moral conscience	0.053
Ethics	Population ethics	0.059
Ethics	Reasons	0.068
Ethics	Virtues	0.083
Ethics	Moral norms	0.096
Ethics	Medical ethics	0.098
Ethics	Promises and imperatives	0.138
Ethics	Olp ethics	0.142
Ethics	Value	0.149
Ethics	Free will	0.153
Ethics	Abortion and self-defence	0.175
Ethics	Decision theory	0.224
Ethics	Frankfurt cases	0.407
Metaphysics	Personal identity	0.878
Metaphysics	Origin essentialism	0.914
Metaphysics	Causation	0.920
Metaphysics	Time	0.937
Metaphysics	Temporal paradoxes	0.959
Metaphysics	Classical space and time	0.962
Metaphysics	Modality	0.962
Metaphysics	Composition and constitution	0.970

That works pretty well. There is a very clean split between the ethics subjects and the metaphysics subjects. (I’ll use “subject” from now on to refer to both the topics and the subtopics that are being classified.) The only one vaguely in between is Frankfurt cases, and that even makes sense; until recently free will was a subject in metaphysics textbooks as much as ethics textbooks.

Five caveats before I continue.

First, which category bunches near 0 and which bunches near 1 is completely arbitrary and doesn’t mean anything. What matters is the bunching.

Second, the bunching matters much more than which is on either side of 0.5. Hopefully there will be a big gap in the means somewhere, and that will correspond to a category boundary. But especially when the categories are of different sizes, that gap might be a long way from the midpoint.

Third, this is just a tool. There are going to be cases it gets wrong, and I’ll correct them by hand. But it’s a surprisingly powerful tool, and I’ll defer to it in a lot of close calls.

Fourth, I didn’t just find these categories lying around and used this tool to confirm them. There was a lot of juggling around to get it to a point where most of these automatic classifications agreed with my classifications, and the ones that didn’t were easy enough to explain. And the nature of LDAs is that any change somewhere creates changes everywhere. The methodology here involves a fair bit of trial and error. But some of the methodology is clear enough. Look back at that table. If I’d put Frankfurt cases in metaphysics, the very same test would tell me to move them into ethics. So this method doesn’t just confirm that a classification gets things broadly right, it can say where a classification is going wrong. To be sure, it’s basically an equilibrium method, and it doesn’t rule out other equilibria. But it’s interesting to have found even one.

Fifth, I’m not applying this to three categories: idealism, aesthetics and philosophy of religion. Both aesthetics and philosophy of religion really don’t have borderline cases. And the technique I’m using doesn’t work so well when the categories are of very uneven size. Therefore, it often gives wonky results for those two categories. (It also on occasion gives some of the cleanest splits - but it feels random when it does.) Still, I wasn’t worried about those two categories. And idealism is a special case that I’ll come back to at the end of the chapter.

I’m looking at nine categories to check that the boundaries between them are drawn roughly correctly. And that means there are nine choose two, i.e., thirty-six, boundaries to look at. These are in subsections, not sections, so they don’t show up in the sidebar. I’ve included links here to the list of boundaries that I’ll survey.

Epistemology vs. Ethics

Table 5.6: Table 5.7: Comparing articles in epistemology and ethics.
Category	Subject	Mean Probability
Epistemology	Formal epistemology	0.025
Epistemology	Knowledge	0.069
Epistemology	Arguments	0.136
Epistemology	Justification	0.139
Ethics	Frankfurt cases	0.189
Ethics	Decision theory	0.325
Ethics	Abortion and self-defence	0.348
Ethics	Medical ethics	0.456
Ethics	Forgiveness	0.565
Ethics	Free will	0.622
Ethics	Population ethics	0.740
Ethics	Promises and imperatives	0.794
Ethics	Reasons	0.797
Ethics	Olp ethics	0.850
Ethics	Moral norms	0.874
Ethics	Virtues	0.905
Ethics	Duties	0.921
Ethics	Value	0.950
Ethics	Moral conscience	0.953

I’m doing these in alphabetical order, and that means the first cab off the rank is one of the trickiest. Three of the epistemology topics: formal epistemology, knowledge and justification are clear enough. And most of the ethics topics are clear enough. But there are two that are hard.

One is arguments. Why should this go with epistemology? Everyone uses arguments. I’ve put it in epistemology for three reasons. First, as you can see, the model puts it there. (And we’ll keep seeing that as we look through the comparisons between epistemology and other categories.) Second, once you extract the dualism arguments from the topic, what’s left are primarily papers about what we can learn from arguments. And those feel like epistemology papers to me. And third, there are a few other close calls where I put something that could go in epistemology elsewhere, and getting the overall shape of the graphs right felt like I needed to have one close call go this way.

The other strange one is decision theory. It’s easy to think that would simply go with the other probability papers in epistemology or maybe philosophy of science. But it’s ended up in ethics for two reasons. One is that, as the table shows, that’s where the automatic sorter put it. But the other comes from thinking about what articles are left in that topic. Given that formal epistemology exists as a topic, and that theory testing also exists, there isn’t as much directly about probability in this topic. What is left is primarily papers about value functions. They are very technical questions about value functions, to be sure, but the papers actually in this topic on the whole are more about the “value” part of expected value than the “expected” part. And that isn’t absurd to group in with ethics. Put another way, what we really have in this topic is formal ethics, and it makes sense that goes with ethics.

Epistemology vs. History of philosophy

Table 5.8: Table 5.9: Comparing articles in epistemology and history of philosophy.
Category	Subject	Mean Probability
Epistemology	Formal epistemology	0.029
Epistemology	Justification	0.069
Epistemology	Knowledge	0.074
Epistemology	Arguments	0.190
History of philosophy	Hume	0.644
History of philosophy	Dewey and pragmatism	0.806
History of philosophy	Ancient	0.842
History of philosophy	Early modern	0.902
History of philosophy	Social contract theory	0.912
History of philosophy	Kant	0.916
History of philosophy	Other history	0.948
History of philosophy	Heidegger and husserl	0.971

History is a fairly heterogenous category, and this technique doesn’t work as well with it as the other categories. But it is fairly happy with where the episteology/history boundary is drawn.

Epistemology vs. Logic and mathematics

Table 5.10: Table 5.11: Comparing articles in epistemology and logic and mathematics.
Category	Subject	Mean Probability
Epistemology	Justification	0.063
Epistemology	Knowledge	0.082
Epistemology	Formal epistemology	0.156
Epistemology	Arguments	0.371
Logic and mathematics	Vagueness	0.691
Logic and mathematics	Verification	0.741
Logic and mathematics	Deduction	0.798
Logic and mathematics	Truth	0.813
Logic and mathematics	Analytic/synthetic	0.841
Logic and mathematics	Propositions and implications	0.854
Logic and mathematics	Definitions	0.936
Logic and mathematics	Mathematics	0.950
Logic and mathematics	Universals and particulars	0.964
Logic and mathematics	Sets	0.964

I would have expected the model would have really wanted to put arguments in with logic and mathematics. And it is a bit of a borderline case. But it still clearly puts arguments closer to the epistemology cluster than the logic cluster. And I was surprised that verification didn’t look a bit more like an epistemology topic. I’ll come back to why it ends up in logic and mathematics not anywhere else, but for now it looks like it shouldn’t be an epistemology topic.

Epistemology vs. Metaphysics

Table 5.12: Table 5.13: Comparing articles in epistemology and metaphysics.
Category	Subject	Mean Probability
Metaphysics	Composition and constitution	0.038
Metaphysics	Temporal paradoxes	0.040
Metaphysics	Classical space and time	0.047
Metaphysics	Origin essentialism	0.077
Metaphysics	Causation	0.092
Metaphysics	Personal identity	0.143
Metaphysics	Modality	0.191
Metaphysics	Time	0.342
Epistemology	Arguments	0.767
Epistemology	Formal epistemology	0.830
Epistemology	Justification	0.954
Epistemology	Knowledge	0.955

A lot of philosophers use the phrase “metaphysics-and-epistemology” almost as if it is one long word, with “em-and-ee” being shorthand for an alleged field within philosophy. We don’t really see any such field turning up in this model. The gap between metaphysics and epistemology is as clear as any gap between categories.

Epistemology vs. Philosophy of language

Table 5.14: Table 5.15: Comparing articles in epistemology and philosophy of language.
Category	Subject	Mean Probability
Epistemology	Justification	0.052
Epistemology	Knowledge	0.114
Epistemology	Arguments	0.233
Epistemology	Formal epistemology	0.264
Philosophy of language	Language norms	0.364
Philosophy of language	Belief ascriptions	0.678
Philosophy of language	Speech acts	0.787
Philosophy of language	Radical translation	0.846
Philosophy of language	Meaning and use	0.924
Philosophy of language	Sense and reference	0.936
Philosophy of language	Denoting	0.963

Here is the first occasion I’ve had to overrule the model. It wants to put language norms in with epistemology not philosophy of language. And it could go either way. But I’ve put it with philosophy of language for a couple of reasons. One is that the paradigm articles in this subtopic, which are often by or about Brandom, feel more like language articles than epistemology articles to me. And the other is that when I ran the models with this shifted to epistemology, a lot of the neat divisions we’ve already seen got less neat. Still, this is one of the trickier classifications, and I suspect with another few years of data, the model would have found a norms topic that was properly divided into ethics and epistemology.

Epistemology vs. Philosophy of mind

Table 5.16: Table 5.17: Comparing articles in epistemology and philosophy of mind.
Category	Subject	Mean Probability
Epistemology	Formal epistemology	0.017
Epistemology	Knowledge	0.078
Epistemology	Justification	0.084
Epistemology	Arguments	0.109
Philosophy of mind	Conceivability arguments	0.187
Philosophy of mind	Intention	0.464
Philosophy of mind	Freud	0.500
Philosophy of mind	Olp mind	0.503
Philosophy of mind	Concepts	0.697
Philosophy of mind	Wide content	0.742
Philosophy of mind	Emotions	0.753
Philosophy of mind	Self-consciousness	0.794
Philosophy of mind	Minds and machines	0.840
Philosophy of mind	Perception	0.893
Philosophy of mind	Cognitive science	0.901
Philosophy of mind	Color/colour	0.903
Philosophy of mind	Physicalism	0.916
Philosophy of mind	Psychology	0.978

There are two tricky cases here, and the model has relatively firm opinions on one of them.

One is what to say about conceivability arguments. The binary sort I just ran is not completely sure, but it prefers to put it back in with epistemology. I didn’t do that for a few reasons. One is that the subject matter sure looks like philosophy of mind to me. If papers on zombies aren’t fin de siècle philosophy of mind, I don’t know what is. The other is that there are several reasons to think the model might have gotten confused here. It isn’t surprsing that a technique that relies entirely on string matching puts the knowledge argument in with epistemology. And that’s doubly so when we conceive of epistemology as including the general study of arguments. So this looks like a philosophy of mind topic, and there are reasons to think the model won’t be smart enough to see this. Therefore, I put it in philosophy of mind.

The other tricky case is perception. Or at least I thought it was tricky. When I was trying to sort the topics manually, I had no idea what to do with it. But the model doesn’t have any doubts at all, and I was happy to let it resolve my uncertainty.

Epistemology vs. Philosophy of science

Table 5.18: Table 5.19: Comparing articles in epistemology and philosophy of science.
Category	Subject	Mean Probability
Philosophy of science	Space and time	0.035
Philosophy of science	Quantum physics	0.054
Philosophy of science	Evolutionary biology	0.067
Philosophy of science	Dna	0.069
Philosophy of science	Thermodynamics	0.074
Philosophy of science	Chemistry	0.084
Philosophy of science	Models	0.112
Philosophy of science	Functions	0.218
Philosophy of science	Mechanisms	0.277
Philosophy of science	Explanation	0.368
Philosophy of science	Grue	0.443
Philosophy of science	Theories and realism	0.475
Philosophy of science	Laws	0.536
Philosophy of science	Teleology	0.640
Philosophy of science	Methodology of science	0.682
Philosophy of science	Chance	0.728
Philosophy of science	Theory testing	0.734
Philosophy of science	Game theory	0.758
Epistemology	Arguments	0.949
Epistemology	Formal epistemology	0.957
Epistemology	Justification	0.979
Epistemology	Knowledge	0.987

As someone whose earliest philosophical work sat right on the boundary between epistemology and philosophy of science, I thought that there would be more borderline cases here. But the model wasn’t budging. It’s really certain it wants to put the four epistemology subjcts at one end. And the closest subject to them, game theory, is one that I would have overruled and put back in philosophy of science if it hadn’t got it right. So this looks like a clear split.

I’ve mentioned this before, but I keep being surprised at how well the model separated theory testing from formal epistemology. These have a lot of overlap, and the model does think theory testing is closer to epistemology than most things in philosophy of science. But ultimately it knows how to sort articles into one or the other. I find that remarkable.

Epistemology vs. Social and political

Table 5.20: Table 5.21: Comparing articles in epistemology and social and political.
Category	Subject	Mean Probability
Social and political	Liberal democracy	0.039
Social and political	Egalitarianism	0.046
Social and political	Marx	0.048
Social and political	Feminism	0.048
Social and political	Life and value	0.055
Social and political	History and culture	0.073
Social and political	Political freedom	0.132
Social and political	Law	0.198
Social and political	Race	0.215
Social and political	War	0.294
Epistemology	Arguments	0.917
Epistemology	Justification	0.957
Epistemology	Knowledge	0.971
Epistemology	Formal epistemology	0.982

Maybe if we ran the tape forward to 2020 there would be more papers on the boundary between epistemology and social and political. Social epistemology has, after all, become a thing. But restricting attention to these twelve journals, up to 2013, this frontier wasn’t heavily populated.

Ethics vs. History of philosophy

Table 5.22: Table 5.23: Comparing articles in ethics and history of philosophy.
Category	Subject	Mean Probability
Ethics	Forgiveness	0.032
Ethics	Population ethics	0.037
Ethics	Duties	0.051
Ethics	Decision theory	0.086
Ethics	Reasons	0.089
Ethics	Frankfurt cases	0.089
Ethics	Medical ethics	0.089
Ethics	Abortion and self-defence	0.105
Ethics	Free will	0.137
Ethics	Promises and imperatives	0.151
Ethics	Moral norms	0.172
Ethics	Virtues	0.297
Ethics	Moral conscience	0.310
Ethics	Olp ethics	0.354
History of philosophy	Social contract theory	0.435
Ethics	Value	0.481
History of philosophy	Hume	0.763
History of philosophy	Kant	0.813
History of philosophy	Dewey and pragmatism	0.829
History of philosophy	Ancient	0.922
History of philosophy	Other history	0.939
History of philosophy	Heidegger and husserl	0.964
History of philosophy	Early modern	0.982

A little bit of overlap here, because social contract theory feels as much like a ethics topic to the model as a History topic. But we know that it goes best with the other History topics. I’m not sure why value feels so historical to the model though; it could be that it has so many older papers in it, but that’s not a great reason.

Ethics vs. Logic and mathematics

Table 5.24: Table 5.25: Comparing articles in ethics and logic and mathematics.
Category	Subject	Mean Probability
Logic and mathematics	Mathematics	0.015
Logic and mathematics	Sets	0.020
Logic and mathematics	Truth	0.031
Logic and mathematics	Universals and particulars	0.038
Logic and mathematics	Propositions and implications	0.041
Logic and mathematics	Analytic/synthetic	0.052
Logic and mathematics	Deduction	0.057
Logic and mathematics	Vagueness	0.062
Logic and mathematics	Definitions	0.067
Logic and mathematics	Verification	0.097
Ethics	Decision theory	0.634
Ethics	Value	0.795
Ethics	Frankfurt cases	0.799
Ethics	Promises and imperatives	0.799
Ethics	Olp ethics	0.822
Ethics	Virtues	0.851
Ethics	Medical ethics	0.865
Ethics	Moral conscience	0.867
Ethics	Moral norms	0.895
Ethics	Abortion and self-defence	0.917
Ethics	Free will	0.921
Ethics	Reasons	0.937
Ethics	Duties	0.962
Ethics	Population ethics	0.964
Ethics	Forgiveness	0.988

This one is pretty easy. Note that although the model is a little uncertain about decision theory, it is happy to include it in ethics. This is notable because so much of decision theory is about problems about infinity, so it would not have been a surprise for it to go with logic and mathematics.

Ethics vs. Metaphysics

Table 5.26: Table 5.27: Comparing articles in ethics and metaphysics.
Category	Subject	Mean Probability
Ethics	Forgiveness	0.018
Ethics	Duties	0.031
Ethics	Moral conscience	0.053
Ethics	Population ethics	0.059
Ethics	Reasons	0.068
Ethics	Virtues	0.083
Ethics	Moral norms	0.096
Ethics	Medical ethics	0.098
Ethics	Promises and imperatives	0.138
Ethics	Olp ethics	0.142
Ethics	Value	0.149
Ethics	Free will	0.153
Ethics	Abortion and self-defence	0.175
Ethics	Decision theory	0.224
Ethics	Frankfurt cases	0.407
Metaphysics	Personal identity	0.878
Metaphysics	Origin essentialism	0.914
Metaphysics	Causation	0.920
Metaphysics	Time	0.937
Metaphysics	Temporal paradoxes	0.959
Metaphysics	Classical space and time	0.962
Metaphysics	Modality	0.962
Metaphysics	Composition and constitution	0.970

This is the one I used as an example, and it seems there aren’t really any borderline cases.

Ethics vs. Philosophy of language

Table 5.28: Table 5.29: Comparing articles in ethics and philosophy of language.
Category	Subject	Mean Probability
Philosophy of language	Denoting	0.006
Philosophy of language	Sense and reference	0.019
Philosophy of language	Radical translation	0.025
Philosophy of language	Belief ascriptions	0.049
Philosophy of language	Meaning and use	0.056
Philosophy of language	Speech acts	0.090
Philosophy of language	Language norms	0.268
Ethics	Olp ethics	0.749
Ethics	Promises and imperatives	0.754
Ethics	Virtues	0.783
Ethics	Value	0.806
Ethics	Frankfurt cases	0.819
Ethics	Moral norms	0.822
Ethics	Moral conscience	0.872
Ethics	Decision theory	0.880
Ethics	Reasons	0.903
Ethics	Abortion and self-defence	0.913
Ethics	Medical ethics	0.925
Ethics	Free will	0.930
Ethics	Duties	0.956
Ethics	Population ethics	0.978
Ethics	Forgiveness	0.985

Nothing too surprising here. The contemporary work on slurs might eventually generate a topic that’s a borderline case. Before I thought of dividing topics in two I was somewhat tempted to classify ordinary language philosophy as philosophy of language. We can see here how bad a mistake that would have been.

Ethics vs. Philosophy of mind

Table 5.30: Table 5.31: Comparing articles in ethics and philosophy of mind.
Category	Subject	Mean Probability
Philosophy of mind	Perception	0.015
Philosophy of mind	Color/colour	0.018
Philosophy of mind	Physicalism	0.021
Philosophy of mind	Wide content	0.025
Philosophy of mind	Psychology	0.043
Philosophy of mind	Cognitive science	0.052
Philosophy of mind	Minds and machines	0.081
Philosophy of mind	Concepts	0.092
Philosophy of mind	Olp mind	0.130
Philosophy of mind	Self-consciousness	0.178
Philosophy of mind	Emotions	0.436
Philosophy of mind	Intention	0.471
Philosophy of mind	Freud	0.537
Philosophy of mind	Conceivability arguments	0.558
Ethics	Olp ethics	0.734
Ethics	Value	0.802
Ethics	Moral norms	0.858
Ethics	Virtues	0.864
Ethics	Promises and imperatives	0.876
Ethics	Abortion and self-defence	0.882
Ethics	Medical ethics	0.897
Ethics	Moral conscience	0.897
Ethics	Reasons	0.901
Ethics	Free will	0.902
Ethics	Decision theory	0.912
Ethics	Frankfurt cases	0.912
Ethics	Population ethics	0.970
Ethics	Duties	0.971
Ethics	Forgiveness	0.988

Another clean division, though the gap between the mind topics and the ethics topics was surprisingly small.

I thought intention, at least in the form that it is in these journals, was clearly a philosophy of mind topic. It’s about a special kind of mental state. But it is fairly common to classify it in with ethics. And it is so clearly tied to action theory (which is more or less in ethics), and the doctrine of double effect (which is clearly in ethics) that you can see why. But I still want to treat papers about a distinctive mental state as being in philosophy of mind, and the model more or less agrees with me.

Ethics vs. Philosophy of science

Table 5.32: Table 5.33: Comparing articles in ethics and philosophy of science.
Category	Subject	Mean Probability
Ethics	Forgiveness	0.009
Ethics	Duties	0.014
Ethics	Reasons	0.028
Ethics	Population ethics	0.043
Ethics	Virtues	0.047
Ethics	Moral conscience	0.057
Ethics	Abortion and self-defence	0.061
Ethics	Free will	0.062
Ethics	Promises and imperatives	0.062
Ethics	Moral norms	0.067
Ethics	Olp ethics	0.086
Ethics	Value	0.090
Ethics	Frankfurt cases	0.108
Ethics	Medical ethics	0.123
Ethics	Decision theory	0.290
Philosophy of science	Game theory	0.345
Philosophy of science	Teleology	0.477
Philosophy of science	Mechanisms	0.768
Philosophy of science	Methodology of science	0.782
Philosophy of science	Laws	0.809
Philosophy of science	Functions	0.839
Philosophy of science	Explanation	0.884
Philosophy of science	Chance	0.919
Philosophy of science	Theory testing	0.924
Philosophy of science	Theories and realism	0.943
Philosophy of science	Evolutionary biology	0.947
Philosophy of science	Chemistry	0.960
Philosophy of science	Grue	0.963
Philosophy of science	Thermodynamics	0.968
Philosophy of science	Models	0.969
Philosophy of science	Dna	0.975
Philosophy of science	Space and time	0.987
Philosophy of science	Quantum physics	0.991

I didn’t think of the ethics/philosophy of science boundary as being a particularly hard one to identify. But this ended up being trickier than I expected.

One issue is that teleology has enough language that goes with action theory that it ends up confusing the model.

But the other thing is what to do with decision theory and game theory. The model clearly doesn’t like breaking them up. But the material on game theory that is here is primarily evolutionary game theory as used in philosophy of biology; that’s clearly philosophy of science. And it would be a stretch to say that decision theory, which is well under 0.5, is a philosophy of science topic on this basis. So I think the overall best thing to do is what I actually did do—though I can see why others might prefer something else.

Ethics vs. Social and political

Table 5.34: Table 5.35: Comparing articles in ethics and social and political.
Category	Subject	Mean Probability
Ethics	Frankfurt cases	0.017
Ethics	Reasons	0.036
Ethics	Promises and imperatives	0.048
Ethics	Decision theory	0.119
Ethics	Moral norms	0.130
Ethics	Population ethics	0.145
Ethics	Free will	0.156
Ethics	Abortion and self-defence	0.169
Ethics	Virtues	0.192
Ethics	Olp ethics	0.222
Ethics	Value	0.301
Ethics	Moral conscience	0.327
Ethics	Medical ethics	0.381
Ethics	Duties	0.475
Social and political	Political freedom	0.533
Ethics	Forgiveness	0.566
Social and political	War	0.614
Social and political	Race	0.691
Social and political	Law	0.753
Social and political	Egalitarianism	0.754
Social and political	Feminism	0.756
Social and political	Liberal democracy	0.883
Social and political	Life and value	0.887
Social and political	Marx	0.900
Social and political	History and culture	0.929

Here is where I really appreciated having a model to work with. I still didn’t entirely go along with what the model suggested, but it helped see what were the easy cases and what were the hard cases.

If I had to guess I would have put abortion and self-defence in with ethics and feminism in with social and political. But I’m very glad to have a model, not just a guess, to rely on here. And I would have made the same division with the two topics closely connected to Parfit’s work: population ethics and egalitarianism. But again, I would have been nervous about relying on guesswork, and it was nice to see the model agree.

So what to say about the two subtopics in the middle: political freedom and forgiveness? I think these are in practice reasonably clear cases. If political freedom isn’t a topic in social and political philosophy I don’t know what is. And while there are some papers about social and structural matters in forgiveness, it is enough about individual relations that I think it should go in ethics.

I suspect what’s happened with both of these is that the subtopics aren’t as cleanly separated as they appear. There are enough papers about law in the forgiveness subtopic that the model won’t quite push it all the way into ethics. And there are enough papers about free will in the political freedom subtopic that it won’t push that topic the other way.

A lot of the boundaries here are fuzzy, and this one is fuzzier than most. But I think the division I ended up making looks reasonably plausible.

History of philosophy vs. Logic and mathematics

Table 5.36: Table 5.37: Comparing articles in history of philosophy and logic and mathematics.
Category	Subject	Mean Probability
History of philosophy	Other history	0.057
History of philosophy	Social contract theory	0.058
History of philosophy	Heidegger and husserl	0.081
History of philosophy	Early modern	0.097
History of philosophy	Kant	0.123
History of philosophy	Ancient	0.138
History of philosophy	Dewey and pragmatism	0.275
History of philosophy	Hume	0.315
Logic and mathematics	Analytic/synthetic	0.779
Logic and mathematics	Universals and particulars	0.780
Logic and mathematics	Definitions	0.831
Logic and mathematics	Deduction	0.896
Logic and mathematics	Verification	0.897
Logic and mathematics	Mathematics	0.906
Logic and mathematics	Propositions and implications	0.931
Logic and mathematics	Vagueness	0.939
Logic and mathematics	Sets	0.961
Logic and mathematics	Truth	0.974

This one shouldn’t have been hard, and it wasn’t.

History of philosophy vs. Metaphysics

Table 5.38: Table 5.39: Comparing articles in history of philosophy and metaphysics.
Category	Subject	Mean Probability
History of philosophy	Other history	0.034
History of philosophy	Social contract theory	0.078
History of philosophy	Heidegger and husserl	0.083
History of philosophy	Early modern	0.090
History of philosophy	Dewey and pragmatism	0.104
History of philosophy	Kant	0.121
History of philosophy	Ancient	0.127
History of philosophy	Hume	0.298
Metaphysics	Personal identity	0.792
Metaphysics	Time	0.845
Metaphysics	Temporal paradoxes	0.852
Metaphysics	Classical space and time	0.878
Metaphysics	Origin essentialism	0.878
Metaphysics	Causation	0.929
Metaphysics	Modality	0.937
Metaphysics	Composition and constitution	0.949

This one could have been harder, but clearly wasn’t either. Note that the model is sure that neither Heidegger nor Dewey are usefully classified with contemporary metaphysics. That’s what I would have said as well, but I was worried it was a biased take on what metaphysics is.

History of philosophy vs. Philosophy of language

Table 5.40: Table 5.41: Comparing articles in history of philosophy and philosophy of language.
Category	Subject	Mean Probability
History of philosophy	Early modern	0.054
History of philosophy	Kant	0.083
History of philosophy	Other history	0.084
History of philosophy	Heidegger and husserl	0.086
History of philosophy	Ancient	0.096
History of philosophy	Social contract theory	0.186
History of philosophy	Hume	0.239
History of philosophy	Dewey and pragmatism	0.257
Philosophy of language	Meaning and use	0.806
Philosophy of language	Language norms	0.883
Philosophy of language	Denoting	0.922
Philosophy of language	Radical translation	0.922
Philosophy of language	Speech acts	0.951
Philosophy of language	Belief ascriptions	0.970
Philosophy of language	Sense and reference	0.972

And still this is going smoothly. This is all a bit surprising I think. It’s not like there is much in common between the different parts of history, but the binary sorts still end up grouping them all together.

History of philosophy vs. Philosophy of mind

Table 5.42: Table 5.43: Comparing articles in history of philosophy and philosophy of mind.
Category	Subject	Mean Probability
History of philosophy	Other history	0.054
History of philosophy	Social contract theory	0.074
History of philosophy	Early modern	0.106
History of philosophy	Kant	0.114
History of philosophy	Heidegger and husserl	0.151
History of philosophy	Ancient	0.155
History of philosophy	Dewey and pragmatism	0.160
History of philosophy	Hume	0.185
Philosophy of mind	Conceivability arguments	0.359
Philosophy of mind	Freud	0.455
Philosophy of mind	Self-consciousness	0.567
Philosophy of mind	Olp mind	0.641
Philosophy of mind	Physicalism	0.727
Philosophy of mind	Concepts	0.790
Philosophy of mind	Emotions	0.795
Philosophy of mind	Psychology	0.822
Philosophy of mind	Intention	0.840
Philosophy of mind	Minds and machines	0.909
Philosophy of mind	Wide content	0.912
Philosophy of mind	Color/colour	0.914
Philosophy of mind	Perception	0.924
Philosophy of mind	Cognitive science	0.945

And things are still going fairly smoothly. Given how important theories of mind are to some important historical figures, I thought there might be problems here. But it wasn’t.

I don’t know why conceivability arguments ended up seeming so historical. It makes a bit more sense that Freud would feel a bit like a historical topic.

History of philosophy vs. Philosophy of science

Table 5.44: Table 5.45: Comparing articles in history of philosophy and philosophy of science.
Category	Subject	Mean Probability
History of philosophy	Early modern	0.024
Philosophy of science	Space and time	0.050
History of philosophy	Ancient	0.063
History of philosophy	Heidegger and husserl	0.109
Philosophy of science	Quantum physics	0.137
History of philosophy	Other history	0.195
History of philosophy	Kant	0.200
Philosophy of science	Chemistry	0.260
Philosophy of science	Thermodynamics	0.383
History of philosophy	Hume	0.392
Philosophy of science	Laws	0.525
Philosophy of science	Teleology	0.565
History of philosophy	Dewey and pragmatism	0.583
History of philosophy	Social contract theory	0.587
Philosophy of science	Methodology of science	0.708
Philosophy of science	Mechanisms	0.748
Philosophy of science	Explanation	0.775
Philosophy of science	Theories and realism	0.782
Philosophy of science	Grue	0.859
Philosophy of science	Models	0.867
Philosophy of science	Chance	0.896
Philosophy of science	Functions	0.904
Philosophy of science	Dna	0.926
Philosophy of science	Theory testing	0.953
Philosophy of science	Game theory	0.956
Philosophy of science	Evolutionary biology	0.960

And after the last four went so smoothly, this one is a mess. Of all the different boundaries, this is just about the one I was least worried about, and it’s one of the more spectacular failures of my classification tool.

I think what’s happened here is that the binary sort decided that philosophy of physics/philosophy of biology was a more salient dividing line than contemporary philosophy/history of philosophy. So all the physics topics, broadly construed, are at the top of the list, and the biology topics are at the bottom. At least in the parts of history of philosophy that these twelve journals cover, there is a lot more physics-like work than biology-like work, so there is more history at that end. (I’m a bit surprised Ancient ended up at the physics end, I guess.) But both topics from history and topics from philosophy of science that don’t neatly fit on the physics-to-biology spectrum end up clustering in the middle.

Anyway, there weren’t any actual borderline cases here, so it didn’t affect the classification. But we’ll have cause to worry about a similar breakdown in a trickier case soon.

History of philosophy vs. Social and political

Table 5.46: Table 5.47: Comparing articles in history of philosophy and social and political.
Category	Subject	Mean Probability
History of philosophy	Early modern	0.022
History of philosophy	Heidegger and husserl	0.033
History of philosophy	Other history	0.093
History of philosophy	Ancient	0.095
Social and political	History and culture	0.161
History of philosophy	Dewey and pragmatism	0.180
History of philosophy	Kant	0.190
Social and political	Life and value	0.200
History of philosophy	Hume	0.215
Social and political	Marx	0.593
History of philosophy	Social contract theory	0.630
Social and political	Race	0.659
Social and political	Feminism	0.829
Social and political	Law	0.844
Social and political	Political freedom	0.845
Social and political	War	0.880
Social and political	Liberal democracy	0.898
Social and political	Egalitarianism	0.967

This one also isn’t neat, and I think that it’s worth going through the topics one by one to double check that we’ve got everything plausibly located.

The big gap is between Hume and Marx.The default should be that one side of that is history, the other side is social and political.

History and culture really doesn’t feature that many articles about the history of philosophy. It does feature a fair few papers about history, and about the philosophy of history, and I think that’s what confused the model. It’s an easy case, even if the model disagrees.

Life and value is harder. It’s not that it should be in history; there aren’t that many particularly historical papers in it. Remember this topic is something like idealist moral and political philosophy. Now there are some references back to Hegel, and that feels historical. But there are more references to Hegel in idealism. And most of the papers here are trying to put forward first-order philosophical claims, not doing scholarly or exegetical work. I don’t know why this ended up where it did, but it doesn’t feel like a history category.

Marx could have easily been a history topic. But most of the papers here are Marxist analysis of politics and society, not Marx exegesis. I could have gone either way on whether it counted as history or social and political, but I would have tentatively guessed the latter, and it seems the model agrees.

On the other hand, the vast bulk of the papers in social contract theory are clearly history papers. They are history of social and political philosophy, which probably confused the model.

While this is a bit of a mess, the only one that’s really problematic is Life and Value. And I suspect the issue is whether that should be in either of these categories.

Logic and mathematics vs. Metaphysics

Table 5.48: Table 5.49: Comparing articles in logic and mathematics and metaphysics.
Category	Subject	Mean Probability
Logic and mathematics	Truth	0.046
Logic and mathematics	Deduction	0.049
Logic and mathematics	Mathematics	0.088
Logic and mathematics	Propositions and implications	0.099
Logic and mathematics	Sets	0.117
Logic and mathematics	Analytic/synthetic	0.136
Logic and mathematics	Definitions	0.139
Logic and mathematics	Verification	0.214
Logic and mathematics	Universals and particulars	0.269
Logic and mathematics	Vagueness	0.443
Metaphysics	Modality	0.606
Metaphysics	Classical space and time	0.657
Metaphysics	Time	0.817
Metaphysics	Composition and constitution	0.829
Metaphysics	Origin essentialism	0.880
Metaphysics	Personal identity	0.905
Metaphysics	Causation	0.912
Metaphysics	Temporal paradoxes	0.914

This was surprisingly straightforward. I would have put universals and particulars in metaphysics, or maybe philosophy of language. (It is largely about predicates, after all.) But if the model wants to include it with logic and mathematics, I’m not going to disagree.

Conversely, I could just as easily have seen modality go with logic as with metaphysics. But it feels more or less natural to include it in metaphysics given the way it is covered in the late twentieth century. (And it is in the first instance a late twentiety-century topic, at least the way this model classifies things.)

This ends up being a case where the binary sort resolves some hard cases, though probably it resolves them in the way I would have done regardless.

Logic and mathematics vs. Philosophy of language

Table 5.50: Table 5.51: Comparing articles in logic and mathematics and philosophy of language.
Category	Subject	Mean Probability
Logic and mathematics	Mathematics	0.039
Logic and mathematics	Sets	0.041
Logic and mathematics	Deduction	0.122
Logic and mathematics	Analytic/synthetic	0.190
Logic and mathematics	Universals and particulars	0.197
Logic and mathematics	Definitions	0.259
Logic and mathematics	Vagueness	0.338
Logic and mathematics	Verification	0.377
Logic and mathematics	Propositions and implications	0.397
Philosophy of language	Radical translation	0.406
Logic and mathematics	Truth	0.557
Philosophy of language	Denoting	0.644
Philosophy of language	Meaning and use	0.672
Philosophy of language	Language norms	0.880
Philosophy of language	Sense and reference	0.900
Philosophy of language	Belief ascriptions	0.952
Philosophy of language	Speech acts	0.954

When I started this project, I was planning to treat logic and language as a single category. I didn’t want the headache of having to think about whether, say, On Denoting was intended as a contribution to philosophy of language or to logic. But then an earlier version of this technique came up with an incredibly clean division of the topics in what I was calling logic and language into two categories, so I split them up. (And added mathematics to the title of the logic category, since it is the mathematics papers that seem to be most paradigmatic.)

And then I tinkered with things and the split wasn’t so clean any more.

But surprisingly the two in the middle that are “out of order” seem like the cleanest cases in the whole list. When looking through the characteristic papers on truth, they are exemplars of what we’d call contemporary work on logic. And if radical translation isn’t a topic in philosophy of language, then I’m not sure what is. So I’m happy to overrule the model on those two cases.

But I’m also happy to have the model decide for me what to say about denoting, and sense and reference, which I could just as easily have classed as language. And from the other direction, I could easily have put analytic/synthetic, definitions and vagueness into language. But I can see why the model made the choices it did, and I suspect my initial judgments were the result of a somewhat partial acquaintance with each of these topics. So I deferred to it on all those cases.

Logic and mathematics vs. Philosophy of mind

Table 5.52: Table 5.53: Comparing articles in logic and mathematics and philosophy of mind.
Category	Subject	Mean Probability
Logic and mathematics	Sets	0.027
Logic and mathematics	Truth	0.036
Logic and mathematics	Deduction	0.051
Logic and mathematics	Mathematics	0.055
Logic and mathematics	Propositions and implications	0.068
Logic and mathematics	Vagueness	0.074
Logic and mathematics	Definitions	0.179
Logic and mathematics	Analytic/synthetic	0.184
Logic and mathematics	Verification	0.187
Logic and mathematics	Universals and particulars	0.237
Philosophy of mind	Conceivability arguments	0.290
Philosophy of mind	Freud	0.428
Philosophy of mind	Olp mind	0.588
Philosophy of mind	Concepts	0.622
Philosophy of mind	Minds and machines	0.738
Philosophy of mind	Wide content	0.764
Philosophy of mind	Cognitive science	0.811
Philosophy of mind	Color/colour	0.843
Philosophy of mind	Physicalism	0.856
Philosophy of mind	Intention	0.874
Philosophy of mind	Self-consciousness	0.919
Philosophy of mind	Emotions	0.930
Philosophy of mind	Perception	0.941
Philosophy of mind	Psychology	0.968

This seems clean enough. The model gets a bit thrown by conceivability arguments, presumably because it associates arguments with logic. But otherwise intuition and the model line up in these cases.

Logic and mathematics vs. Philosophy of science

Table 5.54: Table 5.55: Comparing articles in logic and mathematics and philosophy of science.
Category	Subject	Mean Probability
Philosophy of science	Dna	0.041
Philosophy of science	Evolutionary biology	0.041
Philosophy of science	Chemistry	0.099
Philosophy of science	Thermodynamics	0.103
Philosophy of science	Mechanisms	0.112
Philosophy of science	Space and time	0.121
Philosophy of science	Models	0.141
Philosophy of science	Functions	0.160
Philosophy of science	Quantum physics	0.199
Philosophy of science	Methodology of science	0.225
Philosophy of science	Game theory	0.246
Philosophy of science	Explanation	0.257
Philosophy of science	Teleology	0.392
Philosophy of science	Theories and realism	0.419
Philosophy of science	Laws	0.522
Philosophy of science	Theory testing	0.594
Philosophy of science	Chance	0.759
Logic and mathematics	Analytic/synthetic	0.842
Logic and mathematics	Mathematics	0.842
Logic and mathematics	Definitions	0.868
Philosophy of science	Grue	0.893
Logic and mathematics	Verification	0.898
Logic and mathematics	Universals and particulars	0.909
Logic and mathematics	Sets	0.932
Logic and mathematics	Vagueness	0.937
Logic and mathematics	Deduction	0.955
Logic and mathematics	Propositions and implications	0.982
Logic and mathematics	Truth	0.986

There are a couple of puzzle cases here, but I think I’m happy to overrule the model in both cases.

One is that the model has a weak preference for putting chance with logic not philosophy of science. This is clearly a mistake—it obviously goes with philosophy of science.

The other is that the model has a strong preference for putting grue with logic. And this is a somewhat more plausible classification. But I think it’s still wrong, for three reasons.

One is that the division here isn’t really between philosophy of science and logic, but between philosophy of biology and logic. All the numbers on the right tell us is where a topic lands on the spectrum from work on, say, the units of selection problem to the semantic paradoxes. It is consistent to say that the grue paradox is more like the semantic paradoxes than it is like the units of selection problem while still saying it is a problem in philosophy of science.

Another is that the model, quite understandably, has a tendency to put any subject matter that includes lots of discussion of conjunctions and disjunctions in with logic. This isn’t entirely wrong, but it is overkill I think. And that’s part of what is driving the classification of grue.

And a third is that the model never really likes splitting up these subtopics, and sets is clearly a logic and mathematics topic, not a philosophy of science topic.

So I’m happy to think there are reasons that the model gets this one case wrong, and also happy that it basically agreed with me on the other twenty-five cases.

Logic and mathematics vs. Social and political

Table 5.56: Table 5.57: Comparing articles in logic and mathematics and social and political.
Category	Subject	Mean Probability
Logic and mathematics	Truth	0.014
Logic and mathematics	Propositions and implications	0.019
Logic and mathematics	Mathematics	0.020
Logic and mathematics	Sets	0.022
Logic and mathematics	Vagueness	0.035
Logic and mathematics	Deduction	0.040
Logic and mathematics	Universals and particulars	0.041
Logic and mathematics	Analytic/synthetic	0.053
Logic and mathematics	Verification	0.056
Logic and mathematics	Definitions	0.061
Social and political	Race	0.661
Social and political	History and culture	0.812
Social and political	War	0.827
Social and political	Law	0.844
Social and political	Life and value	0.853
Social and political	Marx	0.886
Social and political	Political freedom	0.915
Social and political	Feminism	0.946
Social and political	Egalitarianism	0.973
Social and political	Liberal democracy	0.973

A very easy division to make, at least up to 2013. Maybe some of the recent work by folks associated with Pittsburgh and Carnegie Mellon on topics like misinformation, or scientific communities, will complicate this boundary. But up to 2013 it wasn’t complicated at all.

Metaphysics vs. Philosophy of language

Table 5.58: Table 5.59: Comparing articles in metaphysics and philosophy of language.
Category	Subject	Mean Probability
Philosophy of language	Belief ascriptions	0.053
Philosophy of language	Denoting	0.106
Philosophy of language	Sense and reference	0.145
Metaphysics	Modality	0.159
Philosophy of language	Speech acts	0.171
Philosophy of language	Language norms	0.172
Metaphysics	Composition and constitution	0.227
Metaphysics	Origin essentialism	0.357
Metaphysics	Personal identity	0.400
Philosophy of language	Radical translation	0.444
Philosophy of language	Meaning and use	0.752
Metaphysics	Time	0.868
Metaphysics	Causation	0.928
Metaphysics	Classical space and time	0.948
Metaphysics	Temporal paradoxes	0.974

After a lot of successes, here we have a case where the model is of no use at all. And there is one quite tricky case here: modality.

The model is a bit of a mess. There is no way that meaning and use is really a metaphysics topic, contrary to what the model says. And it is very strange to think it puts composition and constitution with philosophy of language. So I don’t give much weight to what it says about modality. But I do give some weight to it, and so I want to look a bit into whether it is right to put it in metaphysics.

Obviously in philosophy of language we do spend a lot of time talking about modals. And the topic, as you can see from the characteristic articles, has a lot of discussion about conditionals. Because pf this, there are reasons to call it a language topic.

But there are stronger reasons to call it a metaphysics topic. Here are some simple statistics to back this up. Of the 370 articles in it, forty-eight of them (about 13 percent) include the string “world” in the title, and fifty-two of them (about 14 percent) include the string “actual” in the title. These feel like they are metaphysics topics. Twenty-four articles are either by Lewis or have “Lewis” in the title, and these are almost all about modal realism. (Though three are by or about C. I. Lewis, and a couple are about counterfactuals.) Fifty of the articles have “dispos” in the title, and while some of them are kind of about conditionals, most of them are clearly metaphysics papers.

While I could see calling this a language topic, it feels more like metaphysics to me, and that’s how I’ve classified it.

Metaphysics vs. Philosophy of mind

Table 5.60: Table 5.61: Comparing articles in metaphysics and philosophy of mind.
Category	Subject	Mean Probability
Metaphysics	Modality	0.051
Metaphysics	Classical space and time	0.059
Metaphysics	Composition and constitution	0.070
Metaphysics	Temporal paradoxes	0.071
Philosophy of mind	Color/colour	0.105
Metaphysics	Time	0.154
Philosophy of mind	Olp mind	0.227
Metaphysics	Origin essentialism	0.245
Philosophy of mind	Perception	0.302
Philosophy of mind	Physicalism	0.367
Metaphysics	Personal identity	0.391
Philosophy of mind	Conceivability arguments	0.411
Metaphysics	Causation	0.419
Philosophy of mind	Concepts	0.611
Philosophy of mind	Psychology	0.731
Philosophy of mind	Minds and machines	0.781
Philosophy of mind	Wide content	0.802
Philosophy of mind	Self-consciousness	0.821
Philosophy of mind	Emotions	0.881
Philosophy of mind	Intention	0.893
Philosophy of mind	Freud	0.901
Philosophy of mind	Cognitive science	0.946

Once again the model doesn’t provide particularly useful guidance. And the problem is clear enough - it thinks of metaphysics of mind as more part of metaphysics than of philosophy of mind. And that’s totally understandable, but I think it isn’t true to how philosophy currently thinks of things.

The really tricky case here is color/colour. That could easily go into metaphysics, since a large number of the papers are about what colors really are. But I’ve put it in mind partially because that’s how I conceive of it, and partially to balance out some close calls going in opposite directions. It’s a small topic so it doesn’t make a huge difference to the category statistics, and I think this is the right way to go, but it would be easy to classify it differently.

Metaphysics vs. Philosophy of science

Table 5.62: Table 5.63: Comparing articles in metaphysics and philosophy of science.
Category	Subject	Mean Probability
Metaphysics	Temporal paradoxes	0.036
Philosophy of science	Space and time	0.054
Metaphysics	Personal identity	0.067
Metaphysics	Time	0.075
Metaphysics	Classical space and time	0.081
Metaphysics	Composition and constitution	0.092
Philosophy of science	Quantum physics	0.103
Metaphysics	Modality	0.165
Metaphysics	Origin essentialism	0.169
Metaphysics	Causation	0.230
Philosophy of science	Thermodynamics	0.301
Philosophy of science	Chemistry	0.342
Philosophy of science	Laws	0.356
Philosophy of science	Teleology	0.590
Philosophy of science	Explanation	0.747
Philosophy of science	Grue	0.748
Philosophy of science	Mechanisms	0.783
Philosophy of science	Models	0.803
Philosophy of science	Theories and realism	0.810
Philosophy of science	Chance	0.848
Philosophy of science	Functions	0.869
Philosophy of science	Methodology of science	0.905
Philosophy of science	Dna	0.936
Philosophy of science	Theory testing	0.943
Philosophy of science	Game theory	0.945
Philosophy of science	Evolutionary biology	0.957

The binary split the model found here wasn’t between philosophy of science and metaphysics, but between physics and biology. So I have to sort some of the cases by hand.

There ended up being two spacetime subjects. What I’ve called space and time is mostly relativistic space and time, and classical space and time is pre-relativistic. Both of these could have gone just as easily in metaphysics as in philosophy of science. So it seemed like some in-between verdict was called for, and the most natural was to put relativistic work into philosophy of science, and prerelativistic work into metaphysics. The binary sort thinks I should also worry about the classification of quantum physics, but a quick look at the articles in that category—or even at which venues it includes—should persuade you otherwise.

Metaphysics vs. Social and political

Table 5.64: Table 5.65: Comparing articles in metaphysics and social and political.
Category	Subject	Mean Probability
Social and political	Liberal democracy	0.014
Social and political	Egalitarianism	0.030
Social and political	Feminism	0.054
Social and political	Law	0.080
Social and political	Marx	0.093
Social and political	War	0.108
Social and political	Political freedom	0.109
Social and political	History and culture	0.188
Social and political	Life and value	0.215
Social and political	Race	0.451
Metaphysics	Personal identity	0.928
Metaphysics	Origin essentialism	0.938
Metaphysics	Causation	0.959
Metaphysics	Time	0.967
Metaphysics	Modality	0.976
Metaphysics	Temporal paradoxes	0.979
Metaphysics	Classical space and time	0.979
Metaphysics	Composition and constitution	0.979

After several hard cases in a row, it’s nice to have a simple classification. In 2020, social ontology is a big subject matter, and saying just where metaphysics ends and social and political philosophy begins is hard. In these journals through 2013, it’s not so hard.

It’s kind of striking how not hard it is. composition and constitution would be one of the most tricky borderline subjects if I ran this study on works in contemporary philosophy. But through 2013 it’s just about the easiest example for the model to classify. philosophy sometimes seems like it is spinning in place, but sometimes it changes fast, and hopefully future studies like this one will be able to track some of those changes.

Philosophy of language vs. Philosophy of mind

Table 5.66: Table 5.67: Comparing articles in philosophy of language and philosophy of mind.
Category	Subject	Mean Probability
Philosophy of language	Denoting	0.033
Philosophy of language	Sense and reference	0.049
Philosophy of language	Belief ascriptions	0.067
Philosophy of language	Speech acts	0.076
Philosophy of language	Radical translation	0.092
Philosophy of language	Language norms	0.144
Philosophy of language	Meaning and use	0.180
Philosophy of mind	Conceivability arguments	0.310
Philosophy of mind	Olp mind	0.491
Philosophy of mind	Concepts	0.506
Philosophy of mind	Wide content	0.617
Philosophy of mind	Freud	0.786
Philosophy of mind	Minds and machines	0.815
Philosophy of mind	Color/colour	0.859
Philosophy of mind	Intention	0.863
Philosophy of mind	Physicalism	0.880
Philosophy of mind	Cognitive science	0.913
Philosophy of mind	Self-consciousness	0.913
Philosophy of mind	Perception	0.917
Philosophy of mind	Emotions	0.931
Philosophy of mind	Psychology	0.975

This table really surprised me. I think of mind and language as close to a single subject matter. At Michigan one of our most popular big lecture courses is called “Mind and Language”. There is a really important journal called Mind and Language. If I was trying to study contemporary philosophy using data mining and not the history of philosophy, I probably would have included that journal because it is so important. It feels like this should be one of the trickiest boundaries to draw.

And yet, it wasn’t. The only subject that gave the model any pause was the subtopic on conceivability arguments. I would have paused a fair bit over wide content, but the model didn’t really worry about it.

The actual classifications the model makes all look right to me. I’m just surprised it was so definitive.

Philosophy of language vs. Philosophy of science

Table 5.68: Table 5.69: Comparing articles in philosophy of language and philosophy of science.
Category	Subject	Mean Probability
Philosophy of science	Quantum physics	0.043
Philosophy of science	Space and time	0.044
Philosophy of science	Thermodynamics	0.051
Philosophy of science	Evolutionary biology	0.052
Philosophy of science	Dna	0.056
Philosophy of science	Models	0.067
Philosophy of science	Chemistry	0.074
Philosophy of science	Theory testing	0.114
Philosophy of science	Chance	0.126
Philosophy of science	Explanation	0.196
Philosophy of science	Mechanisms	0.231
Philosophy of science	Theories and realism	0.235
Philosophy of science	Functions	0.257
Philosophy of science	Methodology of science	0.266
Philosophy of science	Laws	0.286
Philosophy of science	Game theory	0.302
Philosophy of science	Grue	0.408
Philosophy of science	Teleology	0.675
Philosophy of language	Radical translation	0.903
Philosophy of language	Language norms	0.961
Philosophy of language	Meaning and use	0.967
Philosophy of language	Speech acts	0.975
Philosophy of language	Sense and reference	0.979
Philosophy of language	Denoting	0.988
Philosophy of language	Belief ascriptions	0.991

This one, on the other hand, should have been easier. And it mostly was. Once again the model struggled with a subtopic, in this case teleology, but otherwise I don’t see much here to quibble about. Maybe looking forward game theory will become more of a borderline case, but for the most part these are separate disciplines.

Philosophy of language vs. Social and political

Table 5.70: Table 5.71: Comparing articles in philosophy of language and social and political.
Category	Subject	Mean Probability
Social and political	Egalitarianism	0.022
Social and political	Liberal democracy	0.024
Social and political	Marx	0.071
Social and political	Life and value	0.076
Social and political	Political freedom	0.082
Social and political	Feminism	0.083
Social and political	History and culture	0.119
Social and political	Law	0.127
Social and political	War	0.164
Social and political	Race	0.225
Philosophy of language	Language norms	0.850
Philosophy of language	Meaning and use	0.932
Philosophy of language	Speech acts	0.949
Philosophy of language	Radical translation	0.968
Philosophy of language	Belief ascriptions	0.981
Philosophy of language	Sense and reference	0.986
Philosophy of language	Denoting	0.990

And this really brings out the difference between philosophy in 2020 and philosophy in these journals up to 2013. Social and political philosophy of language is one of the fastest growing fields in philosophy. The literature on slurs alone is big enough to be a subject in its own right. But add in work on silencing, on propaganda, on trust, lying and deception, and so on, and you have a huge body of work that should be hard to clearly sort into one of these categories. And in the journals up to 2013, we see virtually none of it. Let’s look back at this when we have some more data and see how populated this boundary gets.

Philosophy of mind vs. Philosophy of science

Table 5.72: Table 5.73: Comparing articles in philosophy of mind and philosophy of science.
Category	Subject	Mean Probability
Philosophy of science	Quantum physics	0.045
Philosophy of science	Thermodynamics	0.048
Philosophy of science	Models	0.050
Philosophy of science	Evolutionary biology	0.063
Philosophy of science	Dna	0.064
Philosophy of science	Space and time	0.076
Philosophy of science	Theories and realism	0.123
Philosophy of science	Theory testing	0.126
Philosophy of science	Chance	0.139
Philosophy of science	Chemistry	0.160
Philosophy of science	Explanation	0.191
Philosophy of science	Methodology of science	0.259
Philosophy of science	Grue	0.262
Philosophy of science	Functions	0.267
Philosophy of science	Laws	0.363
Philosophy of science	Mechanisms	0.485
Philosophy of science	Game theory	0.516
Philosophy of mind	Freud	0.587
Philosophy of mind	Cognitive science	0.589
Philosophy of science	Teleology	0.754
Philosophy of mind	Minds and machines	0.781
Philosophy of mind	Conceivability arguments	0.798
Philosophy of mind	Physicalism	0.829
Philosophy of mind	Concepts	0.879
Philosophy of mind	Wide content	0.892
Philosophy of mind	Olp mind	0.922
Philosophy of mind	Psychology	0.925
Philosophy of mind	Color/colour	0.929
Philosophy of mind	Intention	0.931
Philosophy of mind	Self-consciousness	0.963
Philosophy of mind	Emotions	0.974
Philosophy of mind	Perception	0.975

This came out a little neater than I expected. It got the subtopic on teleology wrong again, but otherwise it looks pretty good. Given the amount of scientific work that turns up in philosophy of mind, especially in the nineteenth and twenty-first centuries, I thought this would confuse the model more than it did.

Philosophy of mind vs. Social and political

Table 5.74: Table 5.75: Comparing articles in philosophy of mind and social and political.
Category	Subject	Mean Probability
Social and political	Liberal democracy	0.019
Social and political	Egalitarianism	0.022
Social and political	Feminism	0.098
Social and political	Political freedom	0.099
Social and political	Law	0.100
Social and political	War	0.120
Social and political	Marx	0.127
Social and political	History and culture	0.216
Social and political	Race	0.305
Social and political	Life and value	0.340
Philosophy of mind	Freud	0.453
Philosophy of mind	Conceivability arguments	0.712
Philosophy of mind	Intention	0.744
Philosophy of mind	Emotions	0.815
Philosophy of mind	Self-consciousness	0.863
Philosophy of mind	Concepts	0.933
Philosophy of mind	Minds and machines	0.946
Philosophy of mind	Cognitive science	0.950
Philosophy of mind	Psychology	0.952
Philosophy of mind	Olp mind	0.959
Philosophy of mind	Physicalism	0.975
Philosophy of mind	Wide content	0.984
Philosophy of mind	Color/colour	0.987
Philosophy of mind	Perception	0.989

Not many surprises here. The model doesn’t quite know what to do with philosophical articles about Freud. I don’t know what to do with philosophical articles about Freud. But otherwise it doesn’t see a great deal of overlap. Maybe if we ran this study forward some of the recent work on implicit bias would confound it a little.

Philosophy of science vs. Social and political

Table 5.76: Table 5.77: Comparing articles in philosophy of science and social and political.
Category	Subject	Mean Probability
Philosophy of science	Quantum physics	0.007
Philosophy of science	Space and time	0.008
Philosophy of science	Dna	0.016
Philosophy of science	Thermodynamics	0.034
Philosophy of science	Theories and realism	0.042
Philosophy of science	Chemistry	0.044
Philosophy of science	Models	0.047
Philosophy of science	Explanation	0.077
Philosophy of science	Evolutionary biology	0.087
Philosophy of science	Chance	0.098
Philosophy of science	Theory testing	0.100
Philosophy of science	Laws	0.116
Philosophy of science	Grue	0.129
Philosophy of science	Functions	0.130
Philosophy of science	Mechanisms	0.219
Philosophy of science	Methodology of science	0.290
Philosophy of science	Teleology	0.457
Social and political	Race	0.558
Social and political	History and culture	0.678
Philosophy of science	Game theory	0.690
Social and political	Life and value	0.790
Social and political	Marx	0.834
Social and political	Law	0.911
Social and political	War	0.913
Social and political	Political freedom	0.942
Social and political	Feminism	0.943
Social and political	Egalitarianism	0.971
Social and political	Liberal democracy	0.986

The only tricky case here is game theory. Since game theory is in its nature about the study of social groups, it isn’t surprising that the model wans to put it with science and political philosophy. But looking at the particular articles in that topic, which largely focus on evolutionary game theory, I think it’s a much better fit with the other philosophy of biology articles in philosophy of science.

5.4.1 Summary

I’ve spent a bit of time on going over all thirty-six of these boundaries for two reasons.

One is that the classifications of topics into categories is crucial for generating the category graphs. And there were a lot of choices to be made in generating that classification that could have gone either way, and I wanted to lay out a bit why I made the choices that I did.

The other is that looking at these boundaries is a pretty interesting perspective on how the future might fail to resemble the past. One tried and trusted way to make philosophical progress is to start with two areas that aren’t in a lot of contact, and see what happens when you use the tools and methods of each to look at the questions of the other. We’ve gone through a couple of decades of doing that with ethics and epistemology, and I think the results have been very rewarding. The period since this study ends has seen an explosion of work intersecting science and political philosophy with any number of the other fields here: epistemology, metaphysics and philosophy of language being particularly important.

In general, thinking about where the sharp boundaries are in a study like this, and about what kind of work would make those boundaries less sharp, is a useful way to think about where more work could be usefully done.