Is Introspective Knowledge Incorrigible

BY SENSE PERCEPTION we can become aware of the current state of our physical environment, including our own body. It is very natural to say that, in similar fashion, we can become aware of the current events in our own minds. Instead of turning outward to physical events, the mind turns inward on itself and perceives a procession of mental events. Locke spoke of the faculty of reflection, Kant spoke of inner sense, modern philosophy often speaks of introspection. I believe this traditional view to be essentially correct. But, it is often held, introspection differs from sense perception in one very important respect. Introspective reports of current mental events are alleged to be logically incorrigible or logically indubitable. If I make the sincere statement "I seem to be seeing something green now," then, it is alleged, it is logically impossible for me to be mistaken in my statement. I may be lying, of course, but then I will know that my statement is untrue. For, it is argued, if mistake were a possibility then it would make sense to say "I think I seem to be seeing something green now, but perhaps I am wrong." But this is nonsense, it is said, and so introspection is logically incorrigible or logically indubitable. (In the rest of this paper I shall simply say "incorrigible" or "indubitable," and I shall use the two words interchangeably.) Incorrigibility, or indubitability, must be distinguished from logical necessity. Whether or not the sincere statement "I seem to be seeing something green now" is incorrigible, it is certainly not logically necessary. This is most easily seen if we remember that a logically necessary truth is true in all possible worlds. Now we can certainly describe worlds where I do not seem to be seeing something green now. Contrariwise, it may be noted, a logically necessary statement need not be incorrigible. It is not true that we assent to any logically necessary statement as soon as we understand it. We may mistakenly think it is false. It took a long