This is the first lecture in the 2008 John Locke Lecture series entitled 'Logic, Normativity, and Rational Revisability'.

The sixth lecture will try to resolve a familiar tension between externalism about mental content and the assumption that we have some kind of privileged knowledge of the contents of our own thoughts. I will look at the "slow switching" scenarios, and consider what they show about the role of propositional content in characterizing mental states.

Russell held that we must be acquainted with the constituents of the contents of our thoughts, and remnants of this doctrine persist in the work of a number of more recent philosophers. Our knowledge of our own phenomenal experience is supposed to be a paradigm of acquaintance, but acquaintance is sometimes explained in a way that implies that it involves knowledge of the essential nature of a thing or property.

The fourth lecture will begin with a variation on the thought experiment about Mary that is the focus of the knowledge argument, using it to develop the analogy between self-locating knowledge and knowledge of phenomenal experience. The success of the analogy will turn on the rejection of an assumption that is intuitively plausible, but that I will argue should be rejected.

One strategy for responding to the knowledge argument exploits an analogy between knowledge of phenomenal experience and essentially indexical or self-locating knowledge. I think this is a promising analogy, but I will argue that before we apply it, we need to get clearer about the contents of self-locating belief and knowledge.

The second lecture will begin with Frank Jackson's knowledge argument. The argument and the responses to it turn on assumptions about the nature of the contents of belief and the objects of knowledge. I will argue that one cannot escape the anti-materialist conclusion of the knowledge argument by adopting a fine-grained conception of content.

Our topic is a subject's knowledge of his own phenomenal experience and of the content of his thought, but I will approach the topic from the outside, treating the subject as an object in the world. The first lecture will characterize, in a general way, this externalist strategy, and look at some familiar examples of it in the recent philosophical tradition.