Ethical relativists and subjectivists hold that fact must be distinguished from value, ‘is’ from ‘ought’ and reason from emotion. Their distinctions have been called into question, notably by Philippa Foot (Natural Goodness 2001), also by Alasdair Macintyre (Dependent Rational Animals 1999).

Reason in the form of the life sciences—ethology, biology—indicates that what is good or bad for an individual animal and its species are matters of objective fact. There is nothing relativistic about the idea that fresh meat is good for wolves and it is a fact, a paradigm fact, that polluted water is bad for dolphins. Moreover what is good for an animal is often something that is good about it. Sharp ears and great speed are good for deer and are also what makes a deer a good specimen of its kind.

These general remarks apply to the human animal as well as to ‘ordinary’ animals. The good and bad discussed by moral philosophers cannot be radically different from the good and bad known through reason. But if it were it would normally be a remarkably indigent field of study.