"Differences in reaction to toxic substances vary considerably between species so that the value of these tests remains doubtful. Although thalidomide was extensively tested on animals in several countries, its terrible properties were not discovered. Conversely, penicillin, the greatest medical discovery of the century, was not extensively tested on animals before its miraculous therapeutic qualities were demonstrated in human patients. If it had been fully tested on animals its high toxicity for guinea pigs would have almost certainly prevented its clinical use."

“Are there then any moral foundations on which we can all agree, at least to some extent? I believe there are and that they are these: pain is bad, and so, causing unnecessary pain to others is wrong.”

“A sound moral argument requires both factual and moral premises. Yet there has been little intelligent dialogue at either level. The mumbling of slogans must no longer suffice. We must demand more of our leaders …”

“The 1960s revolutions against racism, sexism and classism nearly missed out the animals. This worried me. Ethics and politics at the time simply overlooked the nonhumans entirely. Everyone seemed to be just preoccupied with reducing the prejudices against humans. Hadn’t they heard of Darwin? I hated racism, sexism and classism, too, but why stop there? As a hospital scientist I believed that hundreds of other species of animals suffer fear, pain and distress much as I did. Something had to be done about it. We needed to draw the parallel between the plight of the other species and our own. One day in 1970, lying in my bath at the old Sunningwell Manor, near Oxford, it suddenly came to me: SPECIESISM!”

“Perhaps there is too much talk of justice, equality and liberty in political philosophy, and not enough about suffering. It is suffering that matters morally …”

“olitical policy should be based, not upon mere opinion, nor upon a set of knee jerk reflexes, but upon a scientific concern for the facts and an intelligent and open moral argument.”

“Misleading may be the claims that procedures are carried out under anaesthesia. Restraining devices and paralysing drugs can today be so effective that an anaesthetic is often unnecessary from the purely practical point of view. The risk of giving a dose too large and thereby losing an expensive chimpanzee, for example, may often tempt a scientist or technician, inexperienced with sophisticated anaesthetic techniques, to give a dose too small, from which the animal quickly recovers — but not of course until after it has been strapped securely to the operating table.”