The Human Phenomenon from the Inside Out: Volume 2: The Knowledge of the Life-World

The first volume of The Human Phenomenon asked what it is to be a subject. This one asks a harder question: once you have an inner life, how do you ever come to know a world you share with other people — and what actually entitles you to call that knowledge?
The book follows a single mind across eight chapters, from the moment it first recognizes something as "the same" — a thread traced from Plato through Douglas Hofstadter's theory of analogy — to the elaborate machinery of consensus by which a scientific community, or a whole society, agrees that something is true. Along the way he gives "sameness" itself an exact logical form, reconstructs and then deliberately pushes past Jürgen Habermas's theory of truth, and extends the result from the laboratory all the way down to the common sense, and the everyday morality, that actually run a life.
Russell, Peirce, Kant, Kuhn, Gellner, Berger and Luckmann, Wittgenstein, Mackie: the conversation is wide, but the argument is one continuous line, not a survey — and each chapter stages the disagreement openly, letting a Defender and a Critic fight it out before the author renders judgment.
For readers who want epistemology that takes a stand, philosophy that treats cognitive science as evidence rather than décor, and abstraction that pays its way in the ordinary business of a life.