The destruction of animals may have two causes; it may be for our defense, it may be for our subsistence. As to the first there is no difficulty; the right of legitimate self-defense authorizes us to destroy what would otherwise destroy us. Between us and beasts injurious to man there is evidently a state of natural war, and in that state the law is that might makes right. This same law is the one which regulates the relations of the animals between themselves: it is also their law in regard to us. The lion, for instance, might not always be as tenderly inclined as the lion of Androcles or the lion of Florence: it would not be well to trust it. We need not, therefore, even theoretically, entertain any scruples concerning the destruction of injurious animals. Is it the same with the destruction of animals intended for our nourishment? Is this destruction innocent, or must we, as did the Pythagoreans or Brahmins of old (for superstitious reasons, however), interdict all animal food?[53] This question has been so well solved by general usage that it is scarcely necessary to raise it. It is not likely men will ever think of giving up animal food, and no one regrets having eaten of a good roast. Yet for those who like to find out the reason of things, it is a problem to know whether we have the right to do what we do without remorse and scruples; and whether a universal and apparently indestructible practice is also a legitimate and innocent practice. Man, according to us, in living on flesh, is justified by nature herself, who made him a carnivorous creature. Every being is authorized to perform the acts which result from its organization.[54] The human organization, as the nature of the teeth and the whole digestive system indicate, is prepared to nourish itself with flesh. In many countries even all other nourishment is impossible; there are peoples whose very situation makes them necessarily hunters, fishermen, or shepherds; it is only in some countries highly favored, and, thanks to scientific cultivation, the result of civilization, that vegetable food could be made abundant enough to suffice, and hardly that for large masses of population; for we know quite well what disasters follow upon a scarcity of crops. What would be the result if the human race were deprived of half its means of subsistence? Add to this that, whatever may have been said against it, animal food mixed in a certain measure with vegetable food, is indispensable to the health and vigor of the human race.