Synesius of Cyrene (c.370-c.413) was a Neo-Platonic philosopher who became bishop of Ptolemais in the Cyrenaica. He left behind a small corpus of texts that offer much information about daily life in Late Antiquity, and about the christianization of the Roman world.
The Eulogy of Baldness shows Synesius' lighter side: he defends his baldness against the speech In Praise of Hair by the sophist-philosopher Dio Chrysostom ("tongue of gold").
The text is offered here in the translation by A. Fitzgerald. The green four-digit numbers are page numbers of the Migne edition.
The glimmer of a bald head is a source of light
  Now one thing had almost escaped me, the most fit of all to mention, I refer to the moon and her phases, which the sons of the bald share in name and in form. This moon, so dear to me, begins in the form of a crescent, becomes a half moon, then again is gibbous, and ends by being a full moon. And assuredly those who have found their way to the summit of good fortune I call the 'full moons': it is even lawful to call them 'suns'. For they no longer return to phases,  but continue with a perfect circle shining in the face of those in heaven. As an instance: Odysseus is made sport of by the suitors, striplings with long hair and waning with dissipation, but soon to perish foully, more than a hundred in number, all of them at the hands of one bald man.note[Homer, Odyssey 18.354-355.]
 Him they counsel, when he is torch-bearing and kindling a light produced by man's hand, to desist from his work for that his head sufficed to light the whole house. Now this very thing is the most divine, and is not only like to the gods, but also akin to man, namely to have light and to make it. Of this splendid glitter smoothness is the cause, and smoothness in the head is nothing but the total absence of hair; for at the same moment, one leaves the worse and approaches the better things, just as when we pointed out that there is an antithesis between the corpse and the living being.
 Now life and light, and all such things, belong to the category of the good and are so esteemed to belong. And again, if light is befitting to the bare surface, we must conclude that hair befits darkness, for this perhaps is not logical, but in every respect it is inevitable. Howbeit, we must needs bring some persuasive force to the argument, and not dwell upon the mere cogency of our demonstration. In sooth all men think and say that hair is a natural parasol, and the most noble of poets, Archilochus, in praising it, praises it on the person of a courtesan. These are his words:
And her hair
overshadowed her shoulders and her waist.
 But a shadow is nothing else than darkness, for absence of light is indicated by each of these words; and to those who approach nearer and investigate the matter, it is easy to see that the night is the greatest shadow, the earth opposing, as it does, a barrier to the beams of the sun. But even in the daytime dense forests have no share in light, for they are excessively shaded and bearded with hair.