Patricia Curd

Anaxagoras of Clazomenae (a major Greek city of Ionian Asia Minor), a Greek philosopher of the 5th century B.C.E. (born ca. 500–480), was the first of the Presocratic philosophers to live in Athens. He propounded a physical theory of “everything-in-everything,” and claimed that nous (intellect or mind) was the motive cause of the cosmos. He was the first to give a correct explanation of eclipses, and was both famous and notorious for his scientific theories, including the claims that the sun is a mass of red-hot metal, that the moon is earthy, and that the stars are fiery stones. Anaxagoras maintained that the original state of the cosmos was a mixture of all its ingredients (the basic realities of his system). The ingredients are thoroughly mixed, so that no individual ingredient as such is evident, but the mixture is not entirely uniform or homogeneous.

There are three components in early Greek philosophy that, while not explicitly stated by the Presocratics, taken together provide the support for their confidence about human knowledge. First, there is an analysis of the concept of divinity, originally found in Xenophanes, but picked up by later thinkers, which removes genuine divinity from the traditional gods and places it in the cosmos itself. The second theme, a continuation of the first, is that human beings, having capacities for perception, thought, and understanding, are able to come to know things beyond their limited daily experience. The third is the growing elaboration of the concepts of understanding and knowledge, along with a developing account of intellect and/or soul according to which thinking is an aspect of soul by which human intellect can ‘latch on to’ the structure of nature. The paper is primarily concerned with these notions in Xenophanes and Heraclitus.