An Essay on Humanity to Animals is a 1798 book by English theologian and writer Thomas Young that argues for the moral obligation to treat animals with kindness and compassion. Published in 1798, the book was part of an emerging discourse on animal welfare and moral philosophy in late 18th-century Britain. Drawing on Christian ethics, natural law, and philosophical reasoning, Young challenges the view that animals exist solely for human use, asserting that animals are sentient beings capable of suffering and therefore deserving of moral consideration. He describes animals as possessing natural rights grounded in their ability to feel pain, and contends that these rights impose ethical duties on humans.

The book critiques a range of practices that Young identifies as cruel or unnecessary, including blood sports, hunting, fishing, overwork of horses, and inhumane methods of food production. It also addresses the impact of childhood cruelty to animals and condemns forms of entertainment involving animal suffering. An Essay on Humanity to Animals is considered one of the earliest English-language works to present a sustained ethical argument on behalf of animals, and it has been cited by later writers on animal welfare and animal rights, including Henry Stephens Salt and Edward Payson Evans.

Thomas Young was educated at Trinity College, Cambridge, where he matriculated in 1790 and graduated as 12th Wrangler in 1794. He became a fellow of the college and later served as tutor and senior dean. In 1813, he was appointed Rector of Gilling East, Yorkshire, a position he held until his death in 1835.

An Essay on Humanity to Animals was published early in his career, in 1798, while he was still based at Cambridge.

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 Light of Nature.

The book is structured into a series of chapters, each examining different forms of human cruelty toward animals and the ethical implications of such behaviour. In the opening chapter, Young draws a link between cruelty to animals and broader social violence, arguing that mistreatment of animals fosters insensitivity and a general disposition toward brutality. Emphasising animals' sentience—their capacity to experience pleasure and pain—he contends that this alone creates a moral obligation to treat them with compassion. He describes animal rights as grounded in natural law and divine will, maintaining that animals possess moral claims by virtue of their ability to suffer. Young further argues that the humane treatment of animals is essential to both moral and spiritual well-being, aligning this view with Christian doctrine and natural evidence.

Subsequent chapters address specific practices that Young deems ethically indefensible. He warns against allowing children to harm animals, suggesting that unchecked cruelty in youth can lead to a hardened character. He condemns blood sports and popular entertainments such as bull-baiting, cockfighting, and hunting for sport, criticising them as morally corrupt and socially harmful. Similarly, he opposes fishing and shooting for amusement, arguing that they cause needless suffering and lack justification.

One chapter is devoted to the treatment of horses, which Young praises as loyal and essential to human labour but often subjected to overwork, mutilation, and abuse. He calls for more humane treatment, recognising their intelligence and service. The book also discusses cruelty in food production, including the practice of skinning animals alive, crimping fish, and killing bees during honey extraction, all of which Young condemns as inhumane and unnecessary. He advocates for alternative practices that reduce harm to animals.