At any rate, I really wanted to read Dennett chronologically: start with Content and Consciousness, and then work on from there. But circumstances have conspired against me. However, the self-portrait in Brainchildren says that his focus remains on the problems of content and consciousness, and to this end, The Intentional Stance is all about content while Consciousness Explained is all about ... wait for it ... consciousness. Those well-versed in Dennettiana will see that I'm skipping over his work on determinism and free will, Elbow Room (see? clever little phrase to refer to free will there), but I'll eventually get back to that, as well as his update on the subject Freedom Evolves.
Here's a passage from the self-portrait in Brainchildren:
The first stable conclusion I reached, after I discovered that my speculative forays always wandered in the same place, was that the only thing brains could do was to approximate the responsivity to meanings that we presuppose in our everyday mentalistic discourse. When mechanical push came to shove, a brain was always going to do what it was caused to do by current, local, mechanical circumstances, whatever it ought to do, whatever a God's-eye view might reveal about the actual meanings of its current states. But over the long haul, brains could be designed -- by evolutionary processes -- to do the right thing (from the point of view of meaning) with high reliability. This found its first published expression in Content and Consciousness (1969, sec. 9, "Function and Content") and it remains the foundation of everything I have done since then. As I put it in Brainstorms (1978a), brains are syntactic engines that can mimic the competence of semantic engines.
Now I happen to think that this is absolutely fatal for Dennett. First, he acknowledges that, on naturalistic premises, our brains cannot do what we think they do, what we experience them doing. It can only approximate such activities. It seems that my thirst, my desire to quench it, and my belief that there is some juice in the refrigerator functions as at least a partial explanation of why I went to the fridge, got out the juice, and drank some. But if naturalism is true, then, according to Dennett, our brains only simulate this. It only seems that the meaning of my thoughts causes my action, but that would constitute a semantic engine -- where the meaning is what is making things run. What's actually happening is that it's the little bits of matter moving as they do that causes my action, which constitutes a syntactic engine -- where the individual letters, the smallest constituents that we put together to make meaning, are what is making things run. If you can explain everything by just appealing to the marks on the page, why would you need to appeal to the meaning of the poem that they form? Indeed, how could the meaning cause anything? Only the marks on the page have real, physical existence, and so only the marks can enter into causal relations. As Dennett puts it in his debate with Plantinga, a semantic engine, at least a naturalistic semantic engine, is like a perpetual motion machine: impossible. And rather than see this as an indictment on naturalism, Dennett cheerfully gives up the meaning. I say this is fatal because I think it makes knowledge and rationality impossible, rendering every thought, Dennett's included, suspect.
Incidentally, I couldn't find any reference in Brainstorms to the distinction between syntactic and semantic engines, but I did find it in Elbow Room, so I assume that's a misprint (or a misread on my part). Also incidentally, a large part of my interest in The Intentional Stance will be on chapter 8, "Evolution, Error, and Intentionality" which you can read online here.