bring phusis - concerned with natural phenomena -into line with nomos, the humanly created customs and laws that vary with particular times and localities.
The orators who were trained in such theories were concerned less with the truth of their arguments than with their ability to sway the audience. Thus, the historian Thucydides, in the introduction to his History, bases his reconstruction of political speeches on ta deonta -the things necessary for each speaker to make his case. In doing so, Thucydides shows that the cause of the Peloponnesian War was to be found in certain matters of human nature -a desire for security, honor, and interest -which allowed the Athenian Assembly and other bodies to be led by cunning speakers. Thucydides was describing the unalterable phusis of men, in a world of political interactions defined by the shifting standards of nomos. 
All of this was immediately and directly applicable to matters of law. The Greek word for a law or custom is also "nomos"-the same word used to describe the norms that many sophists saw as arbitrary. In the view of the sophists, the laws are also subjective human constructs that are not better or worse in any absolute sense, but can be manipulated to bring a desired result. In such a climate, the arguments presented to juries became increasingly bent on success rather than truth, and it became acceptable to twist the laws if necessary to prevail. Logic often gave way to arbitrary arguments and appeals to character. The standard for rhetorical excellence was not truth; it was effectiveness at inducing a decision by the crowd. Aristotle, in his Rhetoric, later offered a corrective, distinguishing a rhetorician -one skilled at rhetoric -from a sophist, on the basis of the latter's choices.
The sophists' concern for rhetoric implied active engagement with political affairs, not philosophical withdrawal for the sake of contemplation. The democracy of Athens allowed aspiring political actors to bring their rhetorical skills directly into political discourse before the Assembly and the courts. The major sophists were legal orators as well as political speakers and actors. Major political figures -including those connected to the regime of "The Thirty Tyrants" imposed by Sparta after the defeat of Athens - including Callicles, Theramenes, Charmides, Critias, and Alcibiades. They practiced their methods, and conveyed their ideas, directly before the Assembly. 
In the end, the turn away from the ancestral laws by the Assembly was part and parcel of the turn away from the traditional moral standards by the sophists and their students. As the sophists thought that such norms were the product of arbitrary conventions, so the Assembly acted as if whatever the people decided for the moment defined what was right - and as if the decision-making capacity of the assembled citizens should be unlimited. On one level, the sophists identified a philosophical basis for this development, in the form of subjective moral theories that denied absolute moral standards. On another level, the formation of these theories strengthened the underlying subjectivism that was influencing many of those speaking before the Assembly. The change in Athens's unwritten ethical constitution had warped its legal constitution, and had brought the polis to the brink of political and military disaster. 
4. The Athenian Response to the Crisis The defeat of Athens brought to a climax a powerful two-pronged reaction against such ideas, a reaction that had begun two decades earlier. The first reaction was by those associated with traditional religious cults, who were appalled at the challenge to the gods posed by the sophists and other intellectuals. A fragment by the playwright Euripides -or perhaps by the political leader and student of the sophists, Critias -claims that the gods wer