I took a course in philosophy during my Cognitive Science studies, and our course book (http://www.amazon.com/Philosophy-Mind-Anthology-John-Heil/dp...) was really useful, since they had an original text and a couple of criticisms of that text, sometimes followed by a retort on that criticism. That was really good to get a grasp of the subject, even though I agree with others here that having an excellent teacher did a lot more to get the subject than any book would have.