It is in his celebrated letter to his friend Van Helmont, that Gassendi deals with the irrational assertions of certain physiologists, apparently more devoted to the defence of the orthodox diet than to the discovery of unwelcome truth, as to the character of the human teeth:—
“I was contending,” he writes to his medical friend, “that from the conformation of our teeth we do not appear to be adapted by Nature to the use of a flesh diet, since all animals (I spoke of terrestrials) which Nature has formed to feed on flesh have their teeth long, conical, sharp, uneven, and with intervals between them—of which kind are lions, tigers, wolves, dogs, cats, and others. But those who are made to subsist only on herbs and fruits have their teeth short, broad, blunt, close to one another, and distributed in even rows. Of this sort are horses, cows, deer, sheep, goats, and some others. And further—that men have received from Nature teeth which are unlike those of the first class, and resemble those of the second. It is therefore probable, since men are land animals, that Nature intended them to follow, in the selection of their food, not the carnivorous tribes, but those races of animals which are contented with the simple productions of the earth.... Wherefore, I here repeat that from the primæval institution of our nature, the teeth were destined to the mastication, not of flesh, but of fruits.
As for flesh, true, indeed, it is that man is sustained on flesh. But how many things, let me ask, does man do every day which are contrary to, or beside, his nature? So great, and so general, is the perversion of his mode of life, which has, as it were, eaten into his flesh by a sort of deadly contagion (contagione veluti quâdam jam inusta est), that he appears to have put on another disposition. Hence, the whole care and concern of philosophy and moral instruction ought to consist in leading men back to the paths of Nature.”
Helmont, it seems, had rested his principal argument for flesh-eating, not altogether in accordance with Genesis, and certainly not in accordance with Science, on the presumption that man was formed expressly for carnivorousness. To this Gassendi replied that, without ignoring theological argument, he still maintained comparative Anatomy to be a satisfactory and sufficient guide. He then applies himself to refute the physiological prejudice of Helmont about the teeth, &c. (as already quoted), and begins by warning his friend that he is not to wonder if the self-love of men is constantly viewed by him with suspicion.[121]
“For, in fact, we all, with tacit consent, conspire to extol our own nature, and we do this commonly with so much arrogance that, if people were to divest themselves of this traditional and inveterate prejudice, and seriously reflect upon it, their faces must be immediately suffused with burning shame.”
He repeats Plutarch’s unanswerable challenge:—
“Man lives very well upon flesh, you say, but, if he thinks this food to be natural to him, why does he not use it as it is, as furnished to him by Nature? But, in fact, he shrinks in horror from seizing and rending living or even raw flesh with his teeth, and lights a fire to change its natural and proper condition. Well, but if it were the intention of Nature that man should eat cooked flesh, she would surely have provided him with ready-made cooks; or, rather, she would have herself cooked it as she is wont to do fruits, which are best and sweetest without the intervention of fire. Nature, surely, does not fail in providing necessary provision for her children, according to the common boast. But what is more necessary than to make food pleasurable? And, as she does in the case of sexual love by which she procures the preservation of the species, so would she procure the preservation of the genus.
“Nor let anyone say that Nature in this is corrected, since, to pass over other things, that is tantamount to convicting her of a blunder. Consider how much more benevolent she would be proved to be, in that case, towards the savage beasts than towards us. Again, since our teeth are not sufficient for eating flesh, even when prepared by fire, the invention of knives seems to me to be a strong proof. Because, in fact, we have no teeth given us for rending flesh, and we are therefore forced to have recourse to those non-natural organs, in order to accomplish our purpose. As if, forsooth, Nature would have left us destitute in so essential things! I divine at once your ready reply: ‘think that Nature has given man reason to supply defects of this kind.’ But this, I affirm, is always to accuse Nature, in order to defend our unnatural luxury. So it is about dress—so it is about other things.