Abstract

The taxonomy of scientific problems constructed by Laudan is not exhaustive of all types of scientific work. For one thing, it does not take into account projects which produce an increase of theoretical virtue in a theory that does not suffer from conceptual problems. It is argued that any work which alters the amount of theoretical virtue possessed by a theory constitutes a scientific advance. A new taxonomy is proposed which distinguishes scientific contributions on the basis of which theoretical virtue is altered, whether the alteration produces an increase or a decrease in virtue, and whether the alteration is due to a logical invention, a logical discovery, or an empirical discovery.