Norm links to the bearded philosophers page at Cambridge and quotes the saying that “A beard does not a philosopher make” (“Barba non facit philosophum”, from over here). It’s a terrific topic. We have a report of this exchange from antiquity, involving the Stoic Epictetus:
“Come now, Epictetus, take off your beard.”
— If I am a philosopher, I answer, I will not take it off.
“Then I will take off your head.”
— If that will do you any good, take it.
And John Sellars tells this story in his book on The Art of Living (2003, p.15):
“In AD 176 the Roman Emperor and Stoic philosopher Marcus Aurelius created four chairs of philosophy in Athens, one for each of the major schools. When, a few years later, the holder of the Peripatetic Chair died, two equally well qualified candidates applied for the post. One of the candidates, Diocles, was already very old so it seemed that his rival, Bagoas, would be sure to get the job. However, one of the selection committee objected to Bagoas on the grounds that he did not have [a] beard saying that, above all else, a philosopher should always have a long beard in order to inspire confidence in his students. Bagoas responded by saying that if philosophers are to be judged only by the length of their beards then perhaps the chair of Peripatetic philosophy should be given to a billy-goat. The matter was considered to be of such grave importance that it was referred to the highest authorities in Rome, presumably to the Emperor himself…”
Over the page, Sellars suggests that it was the mission of the three philosophers to Rome in 155 BCE which created the popular link between philosophers and beards. That was the famous occasion (which haunts Grotius scholarship down to the present day) when the Sceptic Carneades made a speech in favour of justice one day, and a speech against it the next, very much annoying Cato the Censor in the process. But these were bearded Greeks in clean-shaven Rome, and the Romans remembered the beards.
ADDED A FEW MINUTES LATER: Sellars also goes on to note (pp.18-9) that there’s evidence from the ancient sources to suggest that the philosophies of the Greek philosophers shaped the ways in which they wore their beards:
“For example, the Cynics, who preached strict indifference to all external goods and social customs, sported the longest and dirtiest beards. The Stoics, who argued that it is acceptable to prefer certain external goods so long as they are never valued above virtue, also sported long beards, but engaged in occasional washing and trimming for purely practical considerations. The Peripatetics, who following Aristotle believed that external goods and social status were necessary for the good life together with virtue, took great care of their beards, carefully trimming them as appropriate for a member of the traditional Greek aristocracy.”
Presumably this is some kind of ancestor of the debate in the Eastern Orthodox Church about whether holiness resides in a beard, but maybe that only ever existed in my imagination.
Final thing, final thing: I think the Stoics were the ones who were most gripped by the idea that philosophers should have beards, and it’s interesting in this regard that when eighteenth-century French writers were compiling their surveys of women philosophers in antiquity (which were sometimes appended to editions of Diogenes Laertius, presumably for consumption within salon culture, but I don’t really know) that they were able to find evidence of women philosophers belonging to all the different sects except the Stoics. (Lots of good women scholars of Stoicism these days, but that might not be quite the same thing.)