Not so easy to define a human being

Many might feel that one hot psychologist, Steven Pinker, displays the attitude of one who has come up with a remarkable but frightening ability to psychoanalyse the world. But when it came to questioning his views, he readily put his hands up to indicate "don't know" on issues such as those of conscience, personal experience and sin.

Asked how he would define a human being, he said he might initially apply the term "featherless bipedal". He would definitely shirk from attempting a 20th-century dictionary-type definition of the species. He would prefer to point to a human and to another, and link them by their ability to mate collectively.

Yes, within his computational theory and its marriage to the process of natural selection, a normal person does have a conscience somewhere in the information compartmentalisation of the mind. But he could not explain why a person will have a private subjective experience of the world. Nor did he have an answer as to the place, if any, of original sin within the framework.

With some resignation, he said our mental equipment may force us to conceive of problems in ways that will never offer a solution. In contrast, he immediately accepts that people have a belief in souls and religion which is "a mark of the species" everywhere.

Souls and spirits fall into a world we do not fully understand. Some clue to their relevance can be got from observing life and death; "the corpse has something missing that made it animated" when the body was alive.