Functionalists, identity theorists, and at least some dualists have tended to assume that a scientific psychology will employ something like our ordinary ideas of mental states and processes, that it will encompass what Churchland calls “folk psychology.” Churchland, like Davidson, emphasizes the difference between folk psychology and the physical sciences; but, while Davidson has said, “I can imagine a science concerned with people and purged of ‘folk psychology’, but I cannot think in what its interest would consist” (“Knowing One’s Own Mind,” Proceedings and Addresses of the American Philosophical Association, vol. 60, 1987, pp. 447), Churchland is quite ready to see folk psychology “purged” from neuroscience.
Churchland addresses many topics in this paper, and we won’t have a chance to discuss them all. Our focus will be on the arguments against the elimination of folk psychology he notes in section 3, his replies to them in section 4, and the argument and reply noted at the end of section 5.
• The core of Churchland’s argument for the theoretical character of folk psychology appears on p. 232, and the examples of law he gives on p. 233 can give a sense of what he takes its content to be. These laws are stated in symbolic notation, but you can find English translations below.
• Section 2 addresses Churchland’s doubts about folk psychology. It would be safe to focus on the final paragraphs of this section, specifically, on the argument appearing in the second column of p. 235.
• Section 3 is shorter than the rest, clearly structured, and all important.
• Although the title of section 4 suggests a specific further topic, the section turns out to consist of responses to the arguments in section 3. Churchland addresses these in reverse order. His response to the second takes the form of an extended analogy whose moral he begins to draw near the end of p. 238, and he turns to a response to the first argument of section 3 at the end of the first column of p. 239.
• Section 5 consists mainly of a series of science-fiction examples, which do not constitute an argument but may be as good an indication as any of his arguments is of what Churchland thinks we may gain by eliminating folk psychology. The final page of the paper returns to arguments and offers Churchland’s response to one more argument for folk psychology.
A key to Churchland’s symbolic sentences
Churchland states a number of examples of lawlike generalizations of physical and psychological theory using a compact symbolic notation. Here are his examples (using his numbering) restated in a less compact way:
(1) For each particle x, each value f of force, and each value m of mass, if x has mass m and x suffers a net force of f, then x accelerates at f / m
(2) For each person x and proposition p, if x fears that p is true, then x desires that p is not true
(3) For each person x and proposition p, if x hopes that p is true and x discovers that p is true, then x is pleased that p is true
(4) For each person x and propositions p and q, if x believes that p is true and x believes that if p is true then q is true, then, barring confusion, distraction, etc., x believes that q is true
(5) For each person x and propositions p and q, if x desires that p is true and x believes that if q is true then p will be true and x is able to bring it about that q is true, then, barring conflicting desires or preferred strategies, x brings it about that q is true
(6) [This is garbled in Lycan and Prinz, but it’s intended to be identical to (4) above.]
(7) For each volume x of gas, each value P of pressure, each value V of volume, and each quantity µ, if x has pressure P and x has volume V and x has a quantity µ, then, barring very high pressure or density, x has a temperature of PV / µR
(8) For each person x and proposition p, if x desires with all his heart that p is true and x learns that p is not true, then, barring unusual strength of character, x is shattered that p is not true
Meanings of the symbols Churchland uses (A and B are any sentences and … x … is any statement concerning x, which you can understand as the symbolic equivalent of a pronoun):
| Symbol | English Meaning |
| A & B | A and B |
| ~ A | it’s not the case that A |
| A ⊃ B | if A then B |
| (x) … x … | everything, x, is such that … x … |