Ludwig Wittgenstein (1889-1951) was by any reckoning one of the major modern philosophers. Raised as a Catholic in late-19th century Vienna, he later gave up practicing his religion; yet, as journal notes and many anecdotes attest, he remained deeply if ambivalently interested in religion throughout his life. Students of the philosophy of religion are familiar with his lectures on religious belief. For the rest, however, in the vast collection of commentary and criticism that has accumulated over the years, little attention has been paid to his religious interests.