“One commonly notices the unruly independence of this member, interjecting itself so inopportunely when we have no need for it and failing us so inopportunely when we most need it, and contending so imperiously for authority with our will, so haughtily and stubbornly rejecting our urgings, both mental and manual.”
(“On a raison de remarquer l’indocile liberté de ce membre, s’ingerant si importunement, lors que nous n’en avons que faire, et defaillant si importunement, lors que nous en avons le plus affaire, et contestant de l’authorité si imperieusement U avec nostre volonté, refusant avec tant de fierté et d’obstination noz solicitations et mentales et manuelles.“)
I can’t think of anyone who could have written such a classically phrased sentence about such an unclassical topic. Actually, Montaigne goes on to say (in his essay on the Imagination) that in fact this criticism is unfair since all the parts of our body act without our consent. Do we command our hair to stand on end? Or our hearts to beat faster? And he goes on to mention a number of different organs. I can’t help thinking, though, that the one of the main reasons for his adding this was to be able to report the exceptional case of someone who could fart in tune.
Similarly, I find it hard not to mention an anecdote I was once told about “le membre”. At an international committee meeting, a British delegate decided to introduce the new Belgian delegate to the French chairman.
British delegate: Puis-je avoir le plaisir de vous introduire le membre belge?
French chairman: Oui, mais doucement.
“Introduire” in French is a bit different from “introduce” in English, so I suppose you could render it as follows:
British delegate: May I have the pleasure of introducing the Belgian member into you?
French chairman: Yes, but gently.