While quick to question the claims to knowledge that others make, philosophers have not so readily submitted their own affirmations to the same scrutiny. In fact, it seems to be the common conviction of philosophers that the assertions they make are cognitive, are true or false, and that philosophical disagreement is genuine disagreement. In this stimulating essay Professor Lange confronts this assumption, presents his own view of philosophy as proposal, and then seeks a solution to the paradox that his view poses for philosophy. Originally published in 1970. The Princeton Legacy Library uses the latest print-on-demand technology to again make available previously out-of-print books from the distinguished backlist of Princeton University Press. These editions preserve the original texts of these important books while presenting them in durable paperback and hardcover editions. The goal of the Princeton Legacy Library is to vastly increase access to the rich scholarly heritage found in the thousands of books published by Princeton University Press since its founding in 1905.