The idea that when humans are at their worst they behave like wolves has been around a long time. Hobbes used the Latin tag homo homini lupus – man is a wolf to man – to illustrate his belief that unless they are restrained by government, people prey upon one another ruthlessly, while descriptions of rapacious or amoral behaviour as wolfish can be found throughout literature. The notion that evil is the expression of bestial instincts is deeply ingrained, and for the average philosopher as for the average person there is nothing more bestial than the wolf. More generally, a belief in the innate superiority of humans over other animals is part of the Western tradition. Christians tell us that only humans have souls, and though they speak in a different language secular thinkers mostly believe much the same. There are innumerable secular rationalists who, while congratulating themselves on their scepticism, never doubt that the universe is improved by the presence in it of humans like themselves.