Personal purity isn’t really the issue. Not supporting animal abuse – and persuading others not to support it – is.

Were we incapable of empathy – of putting ourselves in the position of others and seeing that their suffering is like our own – then ethical reasoning would lead nowhere. If emotion without reason is blind, then reason without emotion is impotent.

According to the Dominant Western tradition, the natural world exists for the benefit of human beings.

All the particular moral judgments we intuitively make are likely to derive from discarded religious systems, from warped views of sex and bodily functions, or from customs necessary for the survival of the group in social and economic circumstances that now lie in the distant past.

Typically, defenders of experiments on animals do not deny that animals suffer. They cannot deny the animals' suffering, because they need to stress the similarities between humans and other animals in order to claim that their experiments may have some relevance for human purposes. The experimenter who forces rats to choose between starvation and electric shock to see if they develop ulcers (which they do) does so because the rat has a nervous system very similar to a human being's, and presumably feels an electric shock in a similar way.

Do business managers have a commitment to anything more than the success of their company and to making money? It would be hard to say that they do. Indeed, many business leaders deny that there is any conflict between self-interest and the interests of all.

Of course, infanticide needs to be strictly legally controlled and rare - but it should not be ruled out, any more than abortion.