The division between the material and what is not material is made by us. We do not pick it up from the ground as a ready-made axe. The divide between being, as what always exists, and the life of that which comes into being and passes away again, is another result that is not simply an acceptance of what is given. The effort to think about our life is closely bound with the emergence of these sorts of divisions.

The need for discrimination is no less important in modern pursuits of biology and psychology. The models for exchange of information in different systems no longer involve whether it will hurt a foot if kicked. The separation of unconscious and conscious processes does not devolve to the opinions of those who introduced the concept. The limits to introspection versus observation is not something that is the hobby horse of any one theory.

We all lose a certain number of brain cells every day, about 1 cell every second. Tick, tick tick. Since yesterday at this time you have lost 86,400 brain cells. Between the ages of 18 and 91, we lose around 9% of our brains.

A 91 year old may not display many deficits resulting from that missing 9%. On the other hand, a 35 year old with severe brain injury may have lost so many brain cells that he or she no longer recognizes a spouse, children, their surroundings, or self.

Does the person who has lost his or her identity still have one? Does it matter if everyone else knows who this person's identity is, but the subject does not? If I don't know who I am, what good does it do me if there are a million people who know my identity? No good at all!

Our identity is as secure as the structure of our brain. Brain disease, traumatic brain injury, and stroke can wipe out our identity, never to return,

A neurosurgeon, poking around in your brain, could make a bad slice here or there and you would not be present in the recovery room after surgery. Your body would, your brain would, and but for those unfortunately severed connections you would be there too.

The upshot for me is that our identities are quite perishable.