| A sophist (c. 480 - 411 BCE) from Rhamnous who lectured and taught mainly in ancient Athens. He had wide philosophical and scientific interests much like most of his philosophical contemporaries. His most famous works are the Tetralogies, which taught individuals how to make any given side of a lawsuit the strongest position by utilizing good techniques of rhetoric.
The name of Antiphon is associated with many prominent individuals in Athens1 and experts argue over who in this group of men are in fact one in the same. Most scholars agree, however, that the Antiphon known as the orator, sophist, and dream-interpreter are in fact the same man. Antiphon was a contemporary of Socrates and was one of his instructors.2
Antiphon was also known for his advances in the field of mathematics. Most notable was his early attempt to square the circle and so became the first to propose a geometrical method of exhaustion in this manner. 3 Most of our knowledge of Antiphon's mathematical contributions come from Aristotle's comments about him, particularly in his work, Physics.
From his most important legal work, the Tetralogies:
For when God was minded to create the human race and brought the first of us into being, he gave us the earth and sea to sustain and serve us, in order that we might not die for want of the necessaries of life before old age brought us our end. Such being the value placed upon our life by God, whoever unlawfully slays his fellow both sins against the gods and confounds the ordinances of man. 4
He was executed in 411 B.C.E. for his role in the oligarchic, anti-democratic coup of that year.
Most of Antiphon's work has only survived in fragments,5 but among those which have been recovered are:
1 http://www.swan.ac.uk/classics/staff/ter/grst/People/Antiphon.htm
2 Plato. Menexenus. tr. Paul Ryan. Stephanus p. 236 a
3 http://www-groups.dcs.st-andrews.ac.uk/~history/Mathematicians/Antiphon.html
4 Antiphon. Second Tetralogy. tr. K. J. Maidment.
5 To read sections of Antiphon's surviving work, see: http://classics.mit.edu/Browse/browse-Antiphon.html | 
