One of my colleagues and I were discussing these new marvels of modern medical technology. Many of the advances we see were the stuff of science fiction when we were in training. I remember the worldwide media sensation of the first experimental artificial hearts being implanted into humans. Now cardiac assistance devices are becoming fairly commonplace in top tier heart centers around the country. All these new mechanical contraptions got us to wondering what exactly does it mean to be living?
In the past, a person who is breathing and has a heartbeat was considered alive. The romantics ascribed the seat of the soul to the heart. But nowadays medicine has advanced so far ahead of the philosophers that it is hard to describe when life begins and ends. Practically every organ system can now be replaced or transplanted to keep a human body functioning. There are machines to replicate the functions of the heart, lungs, and kidneys. We can give TPN to sustain a person's nutritional status, bypassing the GI tract. There are powerful drugs to supplement our immune systems. We are getting ever closer to manufacturing artificial blood.
At this point only the liver and the brain cannot be replicated mechanically. The liver can be transplanted with a new organ thus prolonging the life of the person. Which leaves only the brain as the sole intractable problem. It alone up to now and into the foreseeable can't be transplanted or replicated. So if every other organ system in the body has been replaced, is the person the same if only his brain is intact? Are we defined merely by a bunch of electrical noise bouncing around billions of neurons within our skulls?
These are questions that bioethicists and philosophers have yet to come to grips with. Medicine is advancing so quickly that even doctors have trouble deciding on questions of life and death. Maybe the Wizard of Oz could have helped us with this difficult dilemma.