Rabbi Sacks points that that modern Games Theory and some neo-Darwinist analyses are finally explaining the rational basis for morality. The article points out that there is actually a rational basis for unselfishness and that a community is more likely to survive than a group of ruthless and completely selfish individuals. It took until now for people to come up with the logical and rational explanation. That is why Hashem had to give us the "logical laws" as commandments in the Torah. If he had not, we were likely to not come up with them on our own (the generation of the Flood is an example of such a society).
As Rabbi Sacks wrote:
In one of the first great works of Jewish philosophy – Sefer Emunot ve-Deot (The Book of Beliefs and Opinions) – R. Saadia Gaon (882-942) explained that the truths of the Torah could be established by reason. Why then was revelation necessary? Because it takes humanity time to arrive at truth, and there are many slips and pitfalls along the way. It took more than a thousand years after R. Saadia Gaon for humanity to demonstrate the fundamental moral truths that lie at the basis of G-d’s covenant with humankind: that co-operation is as necessary as competition, that co-operation depends on trust, that trust requires justice, and that justice itself is incomplete without forgiveness. Morality is not simply what we choose it to be. It is part of the basic fabric of the universe, revealed to us by the universe’s Creator, long ago.