Few people, I imagine, would be disconcerted to learn that it is not very easy to provide a philosophical account of their activities; and this holds no less when these activities are of an intellectual nature. Historians and mathematicians and scientists do not wait in that fashion upon the deliberations of philosophers; and a good thing it is for them, too. For their patience might otherwise be rather severely tried, since disagreement and dispute appear to be the life-blood of philosophy. Nonetheless philosophical questions about these and other activities are not irrelevant to practice.