A GOOD man," said Plutarch, "will take care of his Horses and Dogs, not only while they are young, but when old and past service."

The organs of sense, and consequently feeling itself, are the same as they are in human creatures. I can't imagine how a man not hardened in blood and massacre is able to see a violent death, and the pangs of it, without concern.—Bernard de Mandeville, 1723.

However we may differ as to speculative points of religion, justice is a rule of universal extent and invariable obligation. See that no brute of any kind, whether intrusted to thy care or coming in thy way, suffer through thy neglect or abuse. Let no views of profit, no compliance with custom, and no fear of the ridicule of the world, even tempt thee to the least act of cruelty or injustice to any creature whatsoever. But let this be your invariable rule everywhere, and at all times, to do unto others as, in their condition, you would be done unto.—Humphry Primatt, D. D., 1776.

But a full-grown Horse or Dog is, beyond comparison, a more rational, as well as more conversable animal than an infant of a day, a week, or even a month old. But suppose the case were otherwise, what would it avail? The question is not, Can they reason? nor, Can they talk? but, Can they suffer?—Jeremy Bentham, 1780.

Animals are endued with a capability of perceiving pleasure and pain; and from the abundant provision which we perceive in the world for the gratification of their several senses, we must conclude that the Creator wills the happiness of these his creatures, and consequently that humanity towards them is agreeable to him, and cruelty the contrary. This, I take it, is the foundation of the rights of animals, as far as they can be traced independently of scripture, and is, even by itself, decisive on the subject, being the same sort of argument as that on which moralists found the Rights of Mankind, as deduced from the Lights of Nature.—Thomas Young, 1798.

The claims of the lower animals to humane treatment, or at least to exemption from abuse, are as good as any that man can urge upon man. Although less intelligent, and not immortal, they are susceptible of pain; but because they cannot remonstrate, nor associate with their fellows in defense of their rights, our best theologians and philosophers have not condescended to plead their cause, nor even to make mention of them; although, as just asserted, they have as much right to protection from ill-usage as the best of their masters have.—W. Youatt, 1839.

There is a moral as well as a physical character to all animal life, however humble it may be—enveloped indeed in obscurity, and with a mysterious solemnity which must ever belong to the secrets of the Eternal. Let us then approach with caution the unknown character of the brute, as being an emanation from Himself; and treat with tenderness and respect the helpless creatures derived from such a source.—Ralph Fletcher, 1848.