Conscious Thinking

Intentionality and Rationality

Late 20th-century theories of thought and thinking in the analytic philosophical tradition focused on the problem of how it is that presumably purely physical beings such as ourselves can be in states (or have brains that are in states) that are about things or have “intentionality” and that can bear logical relations to each other such that sequences of them may be rational or irrational.

To say that a mental state is intentional is to say that it has a content—something analogous to the meaning of a sentence. The term intentional is used here in application only to so-called propositional attitudes (beliefs, desires, hopes, etc.) and the constituent thoughts that render them intentional (what they are about), skirting the issue of the intentionality of perceptual and other sensory experiences. The sentence “Blood is red,” for example, has (in English) a particular meaning and in virtue of this meaning (derived from the meanings of its constituent terms) is about blood and says that it is red. The sentence “Mud is brown,” in contrast, has a different meaning and is about something else and says something different about it. Further, these sentences have, in virtue of their meanings, truth conditions—that is, they specify the worldly conditions under which they are true (or false)—as well as logical properties—relations of consistency, inconsistency, and entailment to other sentences. The sentence “Blood is red” is true if and only if blood is red; otherwise, it is false; “Blood is red” and “Mud is brown” are logically consistent with each other (they can both be true); “Blood is red” and “Blood is brown” are not consistent with each other (they can't both be true); and “Blood is red and mud is brown” logically entails “Mud is brown.” Exactly analogous things may be said about the thoughts that blood is red and that mud is brown. Indeed, it is a traditional assumption in analytic philosophy of language that the meanings of sentences derive from (or are) the contents of the thoughts they are (by convention) used to express. Thus, thoughts have contents, which determine their truth conditions and logical relations to each other. (Jerry Fodor has championed the view that we think in a “language of thought,” a system of symbolic representations with sentence-like structures.)