A LIMITED DEFENSE OF THE PESSIMISTIC INDUCTION

The inductive argument from the falsity of most past scientific theori es (more than 100 years old) to the falsity of most present ones is de fensible, I argue, if it is modified to account for the degrees of the oreticity or observationality in such theories, and the extent to whic h they are hedged. The case of descriptive astronomy is examined to sh ow that most of the true theories of the 1890s were high in observatio nality and/or significantly hedged. The false theories of that period, however, were not even approximately true. Apparently, scientists are more interested in supplanting theories with improved observations th an in producing true theories.