INTRODUCTION

In Chapter 7, I offered an answer to the question: How do we know when we are thinking of a substance, and thinking of it unequivocally and nonredundantly? But I did not answer the question, equally urgent: What, on an externalist account, could possibly constitute that one knows what substance one is thinking about? In this chapter, I will try to answer that question.

I will agree with Evans that grasping the identity of the object of one's thought requires having a concept of that object. I have already agreed with him, throughout this book, that a (substance) concept is, in part, an ability to reidentify its object. But abilities, I have said, can be better or worse (Section 4.3). Especially, one can know how to do a thing only under very restricted conditions or under a great variety of conditions. Knowing what one is judging about is thus a matter of degree. One can come to know better what one is judging about.