Occam’s Beard celebrates Brother William of Ockham (1287/8 — 1347), a Franciscan friar and noted medieval scholar to whom the aphorism “entia non sunt multiplicanda sine necessitate” is attributed. Loosely translated as “do not multiply entities without necessity”, it is perhaps best understood by sitting down and drawing your own Rube Goldberg contraption, and then setting that sketch on fire. Over the next few months we’ll examine how this advice applies to modern science, how it fits classical physics like spandex on a superhero, and how it all too often fits modern biology like spandex on Napoleon Dynamite. Because our namesake followed the patron saint of animal behavioural neuroscience, Francis of Assisi, that field may turn out to be over-represented in our blog.

Ockham’s principle is most often referred to as his razor, following a lost, exalted, Franciscan tradition of epistemological utensils (most, like Gaufredi’s Floss—originally made from Gaufredi’s metaphoric sheep tripe—and Caperolo’s oddly prophetic spork, survive in name only, in secondary sources of the French and Scottish Enlightenment). Portraits of Brother William suggest that he applied his razor not just to his beard, but to most of his head, a practice that he sought to justify according to logical principles. Physiology and medicine in Ockham’s era followed a tradition that began with Hippocrates (460 – 370 BC), was passed down through Galen (129 — 199(?) AD), and was finally received through Avicenna, having been, like so much of the Western Canon, preserved by Islamic scribes. The end results of this relay race of knowledge were centuries of blood letting and explosive growth in the leech breeding industry.

Humorism was to a great extent the theoretical foundation of this medical practice. It held that most human health and disease could be explained by the flux and ratios of four bodily fluids (“humors”), yellow bile, phlegm, black bile and blood. An imbalance of humors (dyscrasia) caused illness, and a balance of humors (eucrasia) was the key to a long and healthy life. Humorism, like Lamarck’s giraffe, is easy to mock today, but we should remember that when Hippocrates introduced the idea, it inaugurate the quest for natural causes** in medicine. Ockham, a proto-researcher (that he was summoned to Avignon* to answer charges of heresy testifies to his intellectual rigor), applied his Razor to humorism, the reigning Aristotelian paradigm, and Franciscan grooming habits.

Aristotle, and hence medieval scholastics, held that the heart, not the brain, was the seat of the soul. Ockham speculated that extensive cranial pilosity drew vital humors away from the heart and towards the brain, thereby reducing logical faculties. Thus, Brother William suggested that Franciscan shaving was in part responsible for the Order’s impressive theological erudition. Over the centuries, this idea was thrown into the dustbin of history, lying atop Ptolemaic cosmology, tucked neatly under the efficient market cult. Keen readers will, however, easily spot in this heretical idea the seeds of the expensive tissue hypothesis. The current view of energy budgets in the human body is that two tissues, the brain and the intestine, consume an outsized portion of available glucose, the body’s main immediate fuel source. Biochemist Otto von Glockenspiel, of Fredonia University, in his later, more speculative works published in the Proceedings of the National Academy of Sciences (USA), repeatedly suggested that BS, an orphan receptor in the insulin receptor superfamily, and its ligand Krokof would regulate carbohydrate trafficking between capillary follicles and the carotid and vertebral arteries which, as any schoolchild knows, feed the brain. Thus, Krokof/BS would alternately shunt energy between hair (and beard) growth and cerebral function, providing a molecular basis for Occam’s Beard. This biochemical switch awaits detailed study, and holds great promise for hirsute dimwits both within and without the Tea Party or PSD.

To this day, almost one millennium later, no experimental evidence has directly contradicted Ockham’s Beard energy postulate.


* The Papacy at this point had fled Rome, leading to a series of Popes and Antipopes known as the Western Schism, that was not healed until 1418, when the Pope and the Antipope were in the same room. Subsequent to the emission of gamma rays, positrons and neutrinos the unified papacy returned to the Eternal City.

** Definition may vary according to user. Look up “Theodric of York, Medieval Barber
when you have a moment.


  1. Isn’t it fascinating how some of that ancient wisdom manages to find its explanation in modern science. It also explains why humans are so much smarter than our hairier primate relatives. I do want to note, however, that since shaving may reduce the amount of outwardly visible hair, it does not in fact reduce hair growth itself. Waxing or other more rigorous removal of hair—follicle and all—would probably have been better, but Occam’s Epilady just doesn’t sound as catchy.

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