Abstract

The Triple Life of Ancient Thought Experiments There is no ancient Greek term corresponding to what we nowadays refer to as a thought experiment, and presumably ancient philosophers did not have our modern notion of a thought experiment. But there is no doubt that they did use thought experiments. In fact, they often employed them in ways similar to those of contemporary philosophers, that is, both for defending their own theories as well as for refuting the theories of their opponents. What seems to be particularly intriguing, though, is a third way in which thought experiments were used in antiquity, and particularly in Hellenistic philosophy, namely in order to induce suspension of judgement. For the ancient Sceptics, who wanted to avoid being saddled with dogmatic opinions, made abundant use of thought experiments, not in order to settle philosophical controversies, but in order to formulate arguments of the same strength in support of contradictory beliefs. Indeed, in some cases the hypothetical scenario of one and the same thought experiment was evoked on both sides of a philosophical dispute. Thus, thought experiments were used by ancient philosophers: first, in order to support philosophical theories; second, in order to rebut philosophical theories; and third, in order to induce suspension of judgement. This is what I call the triple life of ancient thought experiments.