"But it is not higher, it is simply biological. The mother is doing it like a robot in the hands of nature. She is helpless – she has to do it. In many animals the father has no instinctive fatherliness; on the contrary, many will kill their own kids and eat them.

"For example in crocodiles, the life of the kids is in immense danger. The mother is protective and fights for the kids' life, but the father just wants to have a good breakfast. The father has no instinct; in fact the father is a human institution.

"The mother crocodile has to keep the kids in her mouth to protect them from the father. She has a big mouth – all women have big mouths – she can manage to keep almost a dozen kids in her mouth. In the mother's mouth, just beside her dangerous teeth the kids are perfectly safe. The more difficult thing is for the kids to figure out who is the mother and who is the father, because they both look alike. And sometimes the kids go close to the father, go into his mouth and are gone forever; then they will never see the light again. But the mother tries to fight, to protect.

"Perhaps that's why nature gives children in such abundance: the mother has one dozen each time, each year. If she can manage to save even two that keeps the population exactly the same, but she manages to protect almost half of the kids.

"Anybody watching will feel that the father is really cruel, has no compassion, no love, and that the mother is really motherly. But you are just projecting your ideas. The mother is protecting, not for any conscious reason; it is in her hormones to protect them, and the father has nothing to do with those hormones. If he is injected with the same hormones then he will stop killing his own kids. So it is a question of chemistry, not of psychology or of anything higher than biochemistry.

"Ninety percent of man's life is still part of the animal world. We live by instinct.

"You fall in love with a woman, or a woman falls in love with you, and you think it is something great."