[SCIENCE CORNER] PHILOSOPHY HALL

_____ _____



The ancient Greek philosopher Thales was born in Miletus in Greek Ionia. Aristotle, the major source for Thales's philosophy and science, identified Thales as the first person to investigate the basic principles, the question of the originating substances of matter and, therefore, as the founder of the school of natural philosophy. He proposed theories to explain many of the events of nature, the primary substance, the support of the earth, and the cause of change. Thales was much involved in the problems of astronomy and provided a number of explanations of cosmological events which traditionally involved supernatural entities.




GEOMETRY (THALES)

Thales was known for his innovative use of geometry. His understanding was theoretical as well as practical. For example, he said:

Megiston topos: hapanta gar chorei.
“Space is the greatest thing, as it contains all things”
Topos is in Newtonian-style space, since the verb, chorei, has the connotation of yielding before things, or spreading out to make room for them, which is extension. Within this extension, things have a position. Points, lines, planes and solids related by distances and angles follow from this presumption.

Thales understood similar triangles and right triangles, and what is more, used that knowledge in practical ways. The story is told in DL (loc. cit.) that he measured the height of the pyramids by their shadows at the moment when his own shadow was equal to his height. A right triangle with two equal legs is a 45-degree right triangle, all of which are similar. The length of the pyramid’s shadow measured from the center of the pyramid at that moment must have been equal to its height.

___________ ___________



A Greek philosopher of the late 6th century BCE, Heraclitus criticizes his predecessors and contemporaries for their failure to see the unity in experience. He claims to announce an everlasting Word (Logos) according to which all things are one, in some sense. Opposites are necessary for life, but they are unified in a system of balanced exchanges. The world itself consists of a law-like interchange of elements, symbolized by fire. Thus the world is not to be identified with any particular substance, but rather with an ongoing process governed by a law of change. The underlying law of nature also manifests itself as a moral law for human beings. Heraclitus is the first Western philosopher to go beyond physical theory in search of metaphysical foundations and moral applications.

Heraclitus' theory can be understood as a response to the philosophy of his Ionian predecessors. The philosophers of the city of Miletus (near Ephesus), Thales, Anaximander, and Anaximenes, believed some original material turns into all other things. The world as we know it is the orderly articulation of different stuffs produced out of the original stuff. For the Milesians, to explain the world and its phenomena was just to show how everything came from the original stuff, such as Thales' water or Anaximenes' air.

Heraclitus seems to follow this pattern of explanation when he refers to the world as "everliving fire" (DK22B30, quoted in full in next section) and makes statements such as "Thunderbolt steers all things," alluding to the directive power of fire (DK22B64). But fire is a strange stuff to make the origin of all things, for it is the most inconstant and changeable. It is, indeed, a symbol of change and process.

Fire is constantly changing-but so is every other stuff. One thing is transformed into another in a cycle of changes. What is constant is not some stuff, but the overall process of change itself. There is a constant law of transformations, which is, perhaps, to be identified with the Logos. Heraclitus may be saying that the Milesians correctly saw that one stuff turns into another in a series, but they incorrectly inferred from this that some one stuff is the source of everything else. But if A is the source of B and B of C, and C turns back into B and then A, then B is likewise the source of A and C, and C is the source of A and B. There is no particular reason to promote one stuff at the expense of the others. What is important about the stuffs is that they change into others. The one constant in the whole process is the law of change by which there is an order and sequence to the changes. If this is what Heraclitus has in mind, he goes beyond the physical theory of his early predecessors to arrive at something like a process philosophy with a sophisticated understanding of metaphysics.