7.1 Topics and Eras

I’ll start by simply listing the ten most popular topics (out of the 90) in each of the five eras. The popularity metric I’m using is the expected number of articles in that topic from that era. So for each era-topic combination, we look at all articles in that era, and sum the probabilities that the article is in that topic. Then we rank the topics by this probability sum, to get the following table.

Table 7.2: Most popular topics in each era
1876-1945 1946-1965 1966-1981 1982-1998 1999-2013
Idealism Ordinary Language Ordinary Language Ordinary Language Ordinary Language
Life and Value Meaning and Use Sets and Grue Arguments Composition and Constitution
Psychology Verification Arguments Justification Norms
Ordinary Language Definitions Promises and Imperatives Theories and Realism Arguments
Other History Idealism Verification Truth Justification
Methodology of Science Methodology of Science Meaning and Use Reasons Modality
Definitions Other History Truth Composition and Constitution Knowledge
Physicalism Life and Value Moral Conscience Causation Evolutionary Biology
Propositions and Implications Moral Conscience Propositions and Implications Modality Truth
Dewey and Pragmatism Universals and Particulars Universals and Particulars Population Ethics Reasons

The striking thing is that Ordinary Language Philosophy comes out top in each era after World War II. This is related to the fact that it is as much a style as a topic, and the style never really went away.

We can also look at the bottom ten topics in each era, by the same metric. (The lowest ranked topics are at the top of this list. Any time I’m listing the lowest ranked anything, I’ll put the lowest at the top.)

Table 7.3: Least popular topics in each era
1876-1945 1946-1965 1966-1981 1982-1998 1999-2013
Formal Epistemology Population Ethics Vagueness Psychology Psychology
Population Ethics Abortion and Self-Defence Wide Content Beauty Heidegger and Husserl
Belief Ascriptions Cognitive Science Races and DNA History and Culture History and Culture
Cognitive Science Wide Content Cognitive Science Races and DNA Beauty
Frankfurt Cases Vagueness Models Social Contract Theory Faith and Theism
Medical Ethics and Freud Races and DNA Psychology Ancient Verification
Game Theory Egalitarianism Game Theory Faith and Theism Idealism
Models Game Theory Hume Analytic/Synthetic Ancient
Abortion and Self-Defence Feminism Kant Functions Social Contract Theory
Norms Models Functions Origins and Purposes Dewey and Pragmatism

That’s not too surprising. Formal epistemology was not a big deal in philosophy pre-1945; Heidegger and Husserl haven’t had much presence in these journals in this century.

But both of these tables, while somewhat useful, have a flaw. The 90 topics aren’t all the same size. So this table is telling us as much about how the model carved up different parts of philosophy, as it is telling us about trends in the field. Here’s a better approach. Take the probablistic measure we just used, and divide it by the size of the topic as a whole. (That is, the expected number of articles in the topic across the whole data set from 1876-2013.) And use that to rank the topics. In effect, within each era we’re ranking the topics by what propoportion of the work on that topic was in that era. So it’s a measure of what were the distinctive topics within each era. Here is what we get.

Table 7.4: Most distinctive topics in each era
1876-1945 1946-1965 1966-1981 1982-1998 1999-2013
Psychology Verification Crime and Punishment Wide Content Models
Idealism Meaning and Use Promises and Imperatives Population Ethics Norms
Life and Value History and Culture Sets and Grue Vagueness Composition and Constitution
Other History Heidegger and Husserl Egalitarianism Cognitive Science Cognitive Science
Self-Consciousness Beauty Intention Belief Ascriptions Formal Epistemology
Physicalism Definitions Duties Abortion and Self-Defence Evolutionary Biology
Dewey and Pragmatism Analytic/Synthetic Radical Translation Justification Vagueness
Beauty Dewey and Pragmatism Speech Acts Reasons Races and DNA
Early Modern Faith and Theism Abortion and Self-Defence Personal Identity Modality
Kant Marx War Radical Translation Population Ethics

And that was a little surprising to me. I had not realised how much the work on Crime and Punishment (in these 12 journals) was concentrated in 1966-1981. If you’d given me 20 guesses for what would be the distinctive topic of this era, probably the era I care most about in all of philosophy, I wouldn’t have guessed this. And I would not have guessed that Promises and Imperatives (which remember includes a lot of deontic logic), and Sets and Grue, would have been second and third.

In general, most of the topics turn up 1-2 eras later than the most famous works in those eras. This makes some sense; the secondary literature has to come after the primary literature. But it means that if your history of philosophy is driven by the great works, you might get a wrong sense of when certain things were being discussed.

Let’s do the same thing but for the topics that have the lowest share of their articles turning up in a given era.

Table 7.5: Least distinctive topics in each era
1876-1945 1946-1965 1966-1981 1982-1998 1999-2013
Formal Epistemology Population Ethics Idealism Idealism Idealism
Population Ethics Cognitive Science Psychology Psychology Psychology
Belief Ascriptions Egalitarianism Wide Content Beauty Heidegger and Husserl
Norms Wide Content Vagueness Life and Value Verification
Cognitive Science Abortion and Self-Defence Other History Verification History and Culture
Radical Translation Vagueness Life and Value Other History Life and Value
Modality Evolutionary Biology Cognitive Science Definitions Meaning and Use
Frankfurt Cases Formal Epistemology Norms History and Culture Beauty
Egalitarianism Composition and Constitution Evolutionary Biology Meaning and Use Definitions
Models Modality Dewey and Pragmatism Universals and Particulars Faith and Theism

For me, the middle column is the most interesting one. The last two columns are pretty much what you’d expect. And the first two columns are as much noise as signal. In the first column the absolute values are all low, and 1 or 2 articles that by coincidence shared some keywords with topics from a century later could move something up or down by several spots. In the second column, the fact that the model doesn’t see consequentialism and utilitarianism as having much in common drives the ‘top’ result.

But in the middle we get an interesting mix. Idealism is over, so all the idealism related topics are relegated. And the journals that are still publishing history are settling on just publishing work on the same few big names, so some history topics are relegated. But other topics have yet to start. It isn’t a surprise that before 1982 there wasn’t much work on Vagueness or on Evolutionary Biology in these journals. (There are important articles in those fields from before 1982, but they don’t tend to be in these 12 journals.) And Norms is as much a style as a topic. But I’m a bit surprised Cognitive Science hadn’t started getting more attention yet. And I’m very surprised that Wide Content is showing up here.

Remember that Putnam’s Meaning and Reference (Putnam 1973) is from the very middle of this era. And given the importance of Twin Earth debates to philosophy of the last 40 years, I would have thought it would have kicked off a huge debate. But it just didn’t. I’ve already discussed this when talking about the Wide Content topic, but it is just shocking to me how long it takes for the literature on Wide Content to really get going.