I've begun reading Putnam's Realism with a Human Face. It's a difficult book, a collection of essays on epistemology, metaphysics, ethics, and history of philosophy, and it interweaves both highly technical discussions about quantum mechanics and logic with a sensitivity to broad cultural and social concerns. It's not that one cannot see the forest for the trees -- one can! -- but that there are so many trees.
In the first section, Putnam provides a quick sketch of two recent developments in quantum mechanics and in the logic of semantic paradoxes. In both cases he examines the temptation of providing a "God's-Eye View," a theory of the totality. In quantum mechanics this temptation expresses itself in the desire for a theory that includes the observer within the system under examination, even at what Putnam considers to be extravagant metaphysical cost (many world interpretation, Bohmian mechanics). In logic this temptation expresses itself in the desire for a resolution of the paradoxes of self-referential sentences.
Putnam concludes that both temptations stem from an evasion of the Kantian lesson: one cannot include oneself within the system, because -- to rephrase the Kantian point in Wittgenstein-esque terms -- the norms of representation are not themselves among the objects represented. Putnam builds on Kant and on Wittgenstein in developing further the failures of metaphysical realism and the turn towards the life of the agent, towards practice or praxis. But, also like Kant and Wittgenstein, Putnam is mindful of the allure of metaphysics.
What is metaphysics? Is metaphysics possible in any sense "after" Kant and Wittgenstein? If so, how?
Next: Hegel and Deleuze as rival versions of self-consciously post-Kantian metaphysics!
And: the secret affinity between Nietzsche, Carnap, and Rorty!