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 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.

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.

Theorizing is of course essential to make progress in understanding, but theorizing in the absence of knowing available relevant facts is not very productive.

Early studies of sleep and dreaming were crucially dependent on waking subjects up during sleep to find out whether they are dreaming or not. Using that strategy, it was found that when the eyes are rapidly moving (REM sleep) people are usually dreaming; when the eyes are not moving, there may be some mentation, but little in the way of visually rich dreams.

I made the assumption, wrong of course, that conceptual analysis was a brief preliminary on the road to finding out about the nature of free will, consciousness, the self, the origin of values, and so forth.

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.