 I owe a profound debt to the Murat Aydede, author of the   previous entry on the same topic. His exposition hugely influenced my work on the entry, figuring indispensably as a springboard, a reference, and a standard of excellence. Some of my formulations in the introduction and in sections 1.1, 2, 3, 4.3, 5, 6.1, and 7 closely track formulations from the previous entry. Section 5’s discussion of connectionism is directly based on the previous entry’s treatment. I also thank Calvin Normore, Melanie Schoenberg, and the Stanford Encyclopedia editors for helpful comments.