If you want to understand the nature of something, to find out the truth, that is one thing. If you want to play semantics, make up wild thought 'experiments', that is another thing. I am not so interested in the latter, though I do appreciate that it can be fun, however unproductive.

It seems probable that humans have been on the planet, with much the same brain, for about 250,000 years.

The neuroscience of consciousness is not going to stop in its tracks because some philosophers guesses that project cannot be productive.

Many mammals and birds have systems for strong self-control, and it is not difficult to see why such systems were advantageous and were selected for. Biding your time, deferring gratification, staying still, foregoing sex for safety, and so forth, is essential in getting food, in surviving, and in successful reproduction.

Remember, in the heyday of vitalism, people said that when all the data are in about cells and how they work, we will still know nothing about the life force - about the basic difference between being alive and not being alive.

It is important to understand that while oxytocin may be the hub of the evolution of the social brain in mammals, it is part of a very complex system. Part of what it does is act in opposition to stress hormones, and in that sense release of oxytocin feels good - as stress hormones and anxiety do not feel good.

Knowing about the neurobiological and evolutionary basis for social behavior can soften the arrogance and self-righteousness that often attends discussions of morality. It may help us all to think a little more carefully and rationally.