He 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 – he wrote that he thought of the word while lying in the bath in the Old Manor House in Sunningwell, Oxfordshire. 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. Ryder was also addressing the general attitude that excluded all nonhumans from the protections offered to humans, now known as the anti-speciesism critique. Waldau writes that this original definition of the term – in effect, human-speciesism – has been extended by others to refer to the assignment of value to any being on the basis of species membership alone, so that, for example, prioritising the value of chimpanzees over other animals (human-chimpanzee speciesism) might be seen as similarly illogical.