There are many levels of organization in nervous systems. Hence we aim to explain mechanisms at one level in terms of properties and dynamics at a lower level, and to fit that in with the properties at the higher levels.

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.

Even philosophers who did not mind psychology, claimed the brain was irrelevant because it was the hardware, and we only need to know about the software.

Being engaged in some way for the good of the community, whatever that community, is a factor in a meaningful life. We long to belong, and belonging and caring anchors our sense of place in the universe.

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

It is surely important that the differences between coma, deep sleep, being under anesthesia, on the one hand, and being alert on the other, all involve changes in the brain.

It seems that the brain has a "small world" architecture - or at least the cortex does. Everything can connect to everything else in a few synaptic steps.