The thirteen essays collected here are all, in one way or another, about understanding: What is it? What does it take to have it? What does it presuppose in what can be understood? In the first group of essays, under the heading Mind, the questions are more specifically about intelligence: First, how can intelligence itself be understood scientifically (as in "cognitive science"); and second, how can the scientific endeavor, so conceived, account for the possibility of a self or subject that understands? Under the second head, Matter, the focus turns to the metaphysical issues surrounding the intelligibility of the mental as a distinctive and irreducible phenomenon in a universe that is, in some sense, ultimately material. The third group of essays, Meaning, addresses the pivotal topics of representation and intentionality, with particular emphasis on the diversity of possibilities - including those that are not symbolic and not internal. The final group, headed Truth, contains the most recent essays. Here the earlier themes come together around the fundamental problem of the metaphysics of mind: What is objective knowledge, and how is it possible? The answer, broached in an exploratory way, amounts to a contemporary revival of transcendental constitution - an idea prominent in the history of philosophy, but largely absent from the recent literature.