It is one of the paradoxes of the current atheism that its leading proponent, Richard Dawkins, argues for a kind of evolved natural law very similar to Aquinas’ synderesis rule which is the foundation of catholic Christian ethics.

“The best way for natural selection to build in both kinds of lust in ancestral times,” argues Dawkins, “was to install rules of thumb in the brain. Those rules still influence us today, even where circumstances make them inappropriate to their original functions. (The God Delusion, page 223).

Reciprocal altruism, where I scratch your back and you scratch mine was in earlier times a survival strategy that allowed bands and groups to flourish by mutual co-operation. As we evolve, argues Dawkins, these become part of the software of our brains, a meme he calls it, which carries on as an instinct long after the instinct has lost its original evolutionary rationale.

So just as we might feel lust even when our partner is on the pill, the original connection being to induce us to reproduce, so our lust to be nice endures long after the original tribal basis has disappeared: we can live alone with few friends but still we experience compassion for the stranger in need, the orphaned child of the Tsumani, the target of the Red Nose Day appeal.

Notice that, just like Aristotelean natural law, this is based on observation – empirical evidence and scientific hypothesis. Aristotle looks at the rational purposes of human beings as evidenced by their behaviour (the behaviour of most rational people, using brains together with natural feelings as their guide). So human beings have a natural desire to reproduce (Aquinas’ primary precept of reproduction) and to co-operate (Aquinas’ primary precept of living in society). According to natural law theory, we also need to inculcate certain virtues in order to flourish (Dawkins might say, evolve successfully, but it comes down to the same broad goal). These virtues might include co-operation, tolerance and kindness, plus a sense of justice that gets revenge on the person who betrays the group. These are social virtues which build communities.

To Dawkins we continue to misfire in our natural lusts – to misfire because it is not very rational to weep for a stranger who has no hope of scratching my back in return. We are like the warbler who feeds the cuckoo chick in their nest driven by a mothering instinct which is irrational – the egg has been quietly popped into the nest – but the bird can’t help itself.

So we can’t help “doing good and avoiding evil” (Aquinas’ definition of synderesis – the innate knowledge of how we should behave): it has been instilled or programmed into us, according to Dawkins, by evolution, according to Aquinas, by God. Both are natural law theorists hypothesising from observable data or the “natural law”.

Click here to read a short extract from the God Delusion.

For a Guardian article discussing these issues as applied to business ethics go to:

http://www.guardian.co.uk/money/2006/may/27/careers.work5