Student of Parmenidhes, Zeno was said to have been one of the teachers of Periklis. His ideas are regarded as precursors to Einstein's theory of relativity, formulated some 2,500 years later. There are various stories about his bravery as a political leader who was involved in insurrection against a tyrant, and refused to betray his comrades during interrogation, suffering torture and/or a brutal excecution. His written works survived him; he is mentioned in the Platonic dialogue named for him, where Plato describes his power to rivet large audiences when speaking in Athens, and particularly the young people. His theories, like those of the Eleatic School in general, involved dialectical paradoxes and riddles, one paradox involving the simultaneous infinite greatness and smallness of every object, the first because the parts into which an object could be divided had to be indivisible, and therefore without magnitude, but infinitely great since the divisions can go on indefinitely. Another paradox concerned the arrow, which was seen as motionless because at any given instant, known as the 'present', it would be only in one place. In addition to foreshadowing Einstein's theory, Zeno's ideas, expressed in his paradoxes, are seen as foreshadowing the antinomies of Emmanuel Kant. Zeno's theories influenced those of Levkippos (Leucippos, above) and some of the Sophists in his own era. A fine saying of his states: Life in agreement with nature is the same as virtuous life, because virtue is the end to which nature leads us.