Many philosophers in the second half of the 20th century really seemed to think that they were laying the foundations for science by laying down the conceptual (necessary) truths.

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

When philosophers try to understand consciousness, much of what they claim is not conceptual analysis at all, though it may be shopped under that description.

Brains are not magical; they are causal machines.

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.

In all probability, mental states are processes and activities of the brain. Exactly what activities, and exactly at what level of description, remains to be seen.

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.