Kenan Malik in Pandaemonium:

Peloponnesian-warHe was ‘the laughing philosopher’ because, wrote Hippolytus, ‘he regarded all human affairs as ridiculous’. Democritus (c460-c370 BCE) was the last of the Presocratics (though many don’t regard him as one), and the most influential. He was born into a wealthy family – so wealthy, it was said, that the Persian king Xerxes paid a visit as his army marched through Democritus’ home town of Abdera in Thrace during his futile attempt to conquer Greece. Democritus spent much of his inherited wealth on travel, satisfying his thirst for knowledge, journeying to Egypt, Ethiopia and as far afield as India. He himself declared that none among his contemporaries had made greater journeys, seen more countries or met more foreign scholars.

In his Lives and Opinions of Eminent Philosophers, the third century biographer Diogenes Laertius tells a story of Democritus deliberately blinding himself in order to be less disturbed in his philosophical pursuits. It is a fanciful tale – old age rather than self-mutilation most likely deprived him of his sight – but it does convey a sense of the awe with which contemporaries regarded both Democritus’ search for truth and the asceticism to which he subjected himself in this pursuit. He was, wrote Cicero ‘as great a man as ever lived’.

Yet, Democritus also came to be the most reviled of the Presocratics. Plato found him so distasteful that he refused to discuss his philosophy and, some claim, even wanted all his works burnt.

More here.