Journal of the History of Philosophy

Within the timespan of two years, two books have been published on the Presocratics as scientists. In 2011 appeared Carlo Rovelli’s The First Scientist. Anaximander and His Legacy, (Yardley: Westholme), and in 2013 Daniel Graham’s Science before Socrates. Whereas Rovelli, whose main field of study is quantum gravity, argues that Anaximander was the first scientist, Graham maintains that Anaximander should not count as a scientist. Empirical science started with Anaxagoras, who used his assumption that solar eclipses occur when the moon blocks its light (“antiphraxis”) to measure the size of the sun on the occasion of a solar eclipse, and to a lesser extent with Parmenides, who recognized that the moon receives its light from the sun (“heliophotism”).

Of course it is all a question of definition. Graham’s is rather strict: “science is (a) a systematic study of the natural world, (b) using an accepted theory and methodology, (c) allowing for open inquiry within (b), (d) permitting elaboration and revision of (b), (e) based on empirical evidence” (256). Rovelli, on the other hand, confronts his view on science with “the dry image of science of some more modern philosophical reflections on science”: “science is a passionate search for always newer ways to conceive the world. Its strength lies not in the certainties it reaches but in a radical awareness of the vastness of our ignorance. … Therefore the scientific quest for knowledge is not nourished by certainty, it is nourished by a radical lack of certainty. … It is able to overthrow the order of things and reconceive the world time and again” (xii).

According to Graham, Anaxagoras saw the eclipse of February 17, 478 BCE, as a proof of the hypothesis of heliophotism. Graham argues that the theories of heliophotism and antiphraxis could not only be empirically tested, but also gloriously withstood the tests. Moreover, Anaxagoras drew several consequences from heliophotism (e.g. that the celestial bodies were fiery stones that moved with an incredible speed, and that the moon is below the sun), which in one stroke wiped out earlier ideas about the nature of the heavenly bodies.

Graham’s example of another scientific effort is less convincing. According to him, the solar eclipse was for Anaxagoras also an opportunity to measure the size of the moon and the sun. The idea is that Anaxagoras could have argued that the shadow of the moon equaled roughly the diameter of the moon, and that he gathered information about where the complete eclipse was observed and where not. However, the eclipse, being annular, could have passed by without being noticed by ordinary people, as Graham himself noticed at the occasion of the annular eclipse of May 20, 2012 CE, of about the same magnitude. Only trained sky watchers could have observed the phenomenon adequately by watching its reflection in a bowl of water or another liquid. This must have diminished significantly the possibility of getting information from elsewhere. Much of the information Anaxagoras needed had to come from people at sea, but it would have been very hard to observe the eclipse in a bowl of water on a heaving ship. Moreover, Graham’s idea implies that Anaxagoras must have presumed that the moon is relatively close to the earth and the sun far away. This cannot be right, because for those who think, like Anaxagoras, that the earth is flat, the sun must necessarily be smaller than the earth and relatively nearby. This can easily be shown by using Thales’s method to calculate the height of a pyramid: draw a line [End Page 835] AS, representing the distance between Athens and a place Somewhere in the south where the sun at the summer solstice is in the zenith. In Athens the sun at that time is at 75.5°. Draw in S the perpendicular pointing toward the sun. Then draw a line from A at an angle of 75.5°. Where this line cuts the perpendicular...