The question is not can animals speak but can they suffer.

What else is it that should trace the insuperable line? Is it the faculty of reason or perhaps the faculty of discourse? 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 or a week or even a month old. But suppose they were otherwise, what would it avail? The question is not, Can they reason?, nor Can they talk? but, Can they suffer? Why should the law refuse its protection to any sensitive being? The time will come when humanity will extend its mantle over everything which breathes.

In the mind of all, fiction, in the logical sense, has been the coin of necessity;—in that of poets of amusement—in that of the priest and the lawyer of mischievous immorality in the shape of mischievous ambition,—and too often both priest and lawyer have framed or made in part this instrument.

He who thinks and thinks for himself, will always have a claim to thanks; it is no matter whether it be right or wrong, so as it be explicit. If it is right, it will serve as a guide to direct; if wrong, as a beacon to warn.

Reputation is the road to power

What is it that should trace the insuperable line? ...The question is not, Can they reason? nor Can they talk? but, Can they suffer?

Natural rights is simple nonsense: natural and imprescriptible rights, rhetorical nonsense—nonsense upon stilts.