 If we think of empiricism as an attitude, rather than a clearly formulated doctrine, then it dates from the very beginnings of Western philosophy, in the work of the Presocratics. Some care is needed here, since we know of the Presocratics only through quotations and reports, found in authors who in some cases lived centuries later and who themselves had philosophical axes to grind. One of our major sources, for instance, is Aristotle. But Aristotle was not trying to compile an historical account; he was attempting to construct his own system and he sometimes reshaped his predecessors’ views with this goal in mind (Cherniss 1935: 347). Judging from the quotations and reports we do have, it would be difficult to describe the Presocratics as empiricists in practice. On the contrary, their claims about the natural world are notoriously sweeping and vague: it is far from clear how they could be tested against experience (Barnes 1982: 48). Some of the Presocratics, however, expressed sentiments that anticipate the doctrinal empiricisms of later times.