The Cry of Nature; or, An Appeal to Mercy and to Justice, on Behalf of the Persecuted Animals

The Cry of Nature; or, An Appeal to Mercy and to Justice, on Behalf of the Persecuted Animals is a 1791 treatise by the Scottish writer and revolutionary John Oswald. It was published in London by J. Johnson and issued with a frontispiece by James Gillray. Combining moral, religious, physiological and philosophical arguments, it advocates vegetarianism on ethical grounds and compassion toward animals, opposing practices such as meat-eating, hunting, vivisection and animal sacrifice. Written partly in defence of Oswald's vegetarianism, the work argues that animals are sentient beings deserving of justice and sympathy, and that cruelty toward them corrupts human morality. Drawing on classical, biblical and non-Western sources, including Hindu ethics and Porphyry's De abstinentia, Oswald presents the exploitation of animals as a moral and cultural decline from an earlier, peaceful state of nature.

The treatise has been interpreted by scholars including Aaron Garrett and John Grey as blending Rousseauian political ideals with philosophical vegetarianism influenced by Indian and Enlightenment thought. Later commentators have described it as challenging human dominion over animals and linking vegetarianism with broader ideas of social reform. The book influenced later advocacy literature; the anonymous 1795 tract Remarks on Cruelty to Animals, printed by George Nicholson, drew extensively on it.