Much as animals suffer in a natural state, much more do they seem to suffer when under the dominion of the generality of men. What suffering in the f… - Lewis Gompertz

[C]ruelty is cruelty under whatever colouring it may appear; and whether exercised on a man or on a fly, cruelty is still cruelty. It matters not whether the victim be furnished with two legs or with four, with wings, with fins, or with arms; where there is sensation, there is subject for cruelty, and in proportion to the degree of sensation will its action operate.

It has been generally, but not always, the custom of naturalists to degrade the powers of dumb animals into mere instinct, and not to allow them reason; and on the other hand to elevate the qualities of man, by entirely disavowing the power of instinct in man, giving him the use of reason alone. It appears to me, that there is such a quality as instinct; by which I understand a desire to do any thing without knowing why, or without having the object in view which it is to reach. I am of opinion that both reason and instinct act in man and also in brutes; and I will even grant that the proportion of reason to instinct is greater in man than in other animals; but that the latter possess a great portion of reason would it seems be absurd to dispute.

Yet we are not always justified in concluding that the killing of animals causes a less number to exist; because some of them are carnivorous, and by being killed they can no longer kill others: while others are graminivorous, and when they can no longer eat up the fruits of the soil, other animals may live upon such fruits instead; still there is no justification of slaughter, as the identical lives are certainly thereby destroyed; and if such an excuse be admitted, it must apply by the same rule to the slaughter even of human beings. But however this may be, it is evident that by far the greatest number of animals live in terror and die by violence from their devourers, and the males also by the attacks of each other, besides pestilence, diseases, accidents and starvation, few living their natural time; while by means of many being sacrificed, a few are enabled to live like in a ship of short provision, though without an equitable casting of lots, but by the law of force over weakness; and this law not being confined to dumb animals, but ruling the lots of man as well as of animals, though its operations on human life may be more concealed, but here also population is kept in check by want of food and by warfare; among mankind itself justice is little more than a name, might being the chief law observed: here, too, the strong destroy and oppress the weak; some are enabled to live and multiply, while many starve and live in celibacy to prevent an overflow, which, notwithstanding, does arise: dispute and warfare then result in which some are destroyed and some preserved. But no person, however virtuous, can live in comfort without consuming more than his share. Such is the world we live in, however Pope may contend that "virtue alone is happiness below."