Abstract

Many philosophers of the last century thought all moral judgments can be expressed using a few basic concepts — what are today called ‘thin’ moral concepts such as ‘good,’ ‘bad,’ ‘right,’ and ‘wrong.’ This was the view, fi rst, of the non-naturalists whose work dominated the early part of the century, including Henry Sidgwick, G.E. Moore, W.D. Ross, and C.D. Broad. Some of them recognized only one basic concept, usually either ‘ought’ or ‘good’; others thought there were two. But they all assumed that other moral concepts, including such ‘thick’ ones as the virtue-concepts ‘courageous’ and ‘kindly,’ can be reductively analyzed using one or more thin concepts and some more or less determinate..