On Hypotheses

Abstract

The middle section of the Traité des systèmes contains Condillac’s condemnation not only of metaphysical systems founded upon abstract principles, but also of those systems based on philosophical hypotheses. Unlike abstract principles, which are not really principles at all, but are, as the term “abstract” tells us, derived from prior knowledge, hypotheses can be first principles, provided that they have been confirmed by observation and experiment.¹ Just as there are, in Condillac’s opinion, good and bad systems, there are good and bad hypotheses. Chapter XII of the Traité is by no means a blanket condemnation of all kinds of hypotheses, as many in the following century thought. On the contrary, valid hypotheses are lauded by Condillac as a very necessary part of scientific method. While abstract principles are at best useless, and at worst dangerous, hypotheses can be useful; their use can be said to be “même absolument nécessaire.”² The important thing is what constitutes their validity. It is just as extreme, maintains Condillac, to accept all hypotheses as principles from which to deduce facts about the phenomenal world, as it is to deny them a place in the sciences. Two conditions must exist to ensure the truth of a hypothesis. First, all other possible explanations must be exhausted, and secondly, we must have a means of confirming or rejecting our choice. In so far as these two conditions are fulfilled, hypotheses have a legitimate role to play in the sciences.