Richard Hood Jack Dudley Ryder (born 3 July 1940) is an English writer, psychologist, and animal rights advocate.

In 1977, he became chairman of the RSPCA Council, serving until 1979, and helped to organize the first academic animal-rights conference, held in August 1977 at Trinity College, Cambridge.

[14] Ryder became involved with the group—which he later called the "Oxford Group"—and became an activist for animal rights, organising meetings and printing and handing out leaflets.

[11] Ryder first used the term speciesism in a privately printed leaflet by the same name, which he distributed in Oxford in 1970 in protest against animal experimentation;[16] he wrote that he thought of the word while lying in the bath in the Old Manor House in Sunningwell, Oxfordshire.

[17] Paul Waldau writes that Ryder used the term in the pamphlet to address experiments on animals that he regarded as illogical, and which, he argued, a fully informed moral agent would challenge.

[18] He argued that speciesism is as illogical as racism, writing that "species" and "race" are both vague terms, and asked: "If, under special conditions, it were one day found possible to cross a professor of biology with an ape, would the offspring be kept in a cage or in a cradle?

[19]Singer's use of the term popularised it, and in 1985 became an entry in the Oxford English Dictionary, described as "discrimination against ... animal species by human beings, based on an assumption of mankind's superiority".

They sought to secure the election of reformers – including Ryder and Andrew Linzey, the Oxford theologian – to the RSPCA's ruling council.

[21] Ryder coined the term painism in 1990 to describe his position that all beings who feel pain deserve rights.

[22] He argues that painism can be seen as a third way between Peter Singer's utilitarian position and Tom Regan's deontological rights view.

[23] It combines the utilitarian view that moral status comes from the ability to feel pain with the rights-view prohibition on using others as a means to an end.

He wrote in The Guardian in 2005: "One of the problems with the utilitarian view is that, for example, the sufferings of a gang-rape victim can be justified if the rape gives a greater sum total of pleasure to the rapists."