Animal rights is the philosophy according to which many or all sentient animals have moral worth independent of their utility to humans, and that their most basic interests—such as avoiding suffering—should be afforded the same consideration as similar interests of human beings. Broadly speaking, and particularly in popular discourse, the term "animal rights" is often used synonymously with "animal protection" or "animal liberation". More narrowly, "animal rights" refers to the idea that many animals have fundamental rights to be treated with respect as individuals—rights to life, liberty, and freedom from torture that may not be overridden by considerations of aggregate welfare.
A captive monkey in Shanghai
Chickens held inside a battery cage in a factory farm
Parshvanatha, the 23rd Tirthankara, revived Jainism and ahimsa in the 9th century BCE, which led to a radical animal-rights movement in South Asia.
The c. 5th-century CE Tamil scholar Valluvar, in his Tirukkural, taught ahimsa and moral vegetarianism as personal virtues. The plaque in this statue of Valluvar at an animal sanctuary in South India describes the Kural's teachings on ahimsa and non-killing, summing them up with the definition of veganism.
In ethical philosophy, utilitarianism is a family of normative ethical theories that prescribe actions that maximize happiness and well-being for the affected individuals. In other words, utilitarian ideas encourage actions that ensure the greatest good for the greatest number. Although different varieties of utilitarianism admit different characterizations, the basic idea behind all of them is, in some sense, to maximize utility, which is often defined in terms of well-being or related concepts. For instance, Jeremy Bentham, the founder of utilitarianism, described utility thus:That property in any object, whereby it tends to produce benefit, advantage, pleasure, good, or happiness ... [or] to prevent the happening of mischief, pain, evil, or unhappiness to the party whose interest is considered.
Jeremy Bentham
Peter Singer