Vitalism
From EvoWiki
Vitalism is the theory that living things are alive because they have some nonphysical "vital force" or "life stuff" in them that is distinct from nonliving matter.
Vitalism is a very old theory, and it sometimes seems intuitively obvious. It has had such eminent advocates as Aristotle, who identified three kinds of vital force:
- The Vegetable Soul, responsible for growth and reproduction
- The Animal Soul, responsible for fast motion and response to the environment
- The Rational Soul, responsible for reasoning
- All living things contain the vegetable soul
- All animals contain the animal soul
- Only humanity contains the rational soul
In fairness, if one interprets Aristotle's kinds of soul as capabilities, his schema is half-plausible.
Vitalism continues to survive in the "theoretical justifications" of various "alternative medical therapies", which often feature mysterious "forces" and "energies" like "chi" and "prana". However, those advocating such concepts seem to have little interest in working out who is right about what -- contrary to the practice of mainstream scientists.
However, vitalism has gone steadily downhill in the esteem of mainstream scientists over the last few centuries, to the point that a "vital force of the gaps" hypothesis for biological mysteries is usually considered unthinkable.
A few centuries ago, a common vitalist hypothesis had been that "organic" compounds could only be made from inorganic ones by living things. According to a common stereotyped account, it had been discredited by Friedrich Wöhler's 1828 synthesis of urea from ammonium cyanate. But that was only one synthesis, and nobody attached a greater significance to it back then. But it nevertheless was the beginning of the end for this view; it was followed by numerous other such laboratory inorganic-to-organic syntheses, and this vitalist view was ultimately discredited. Fischer-Tropsch and Urey-Miller syntheses can produce a great variety of organic compounds from a few simple starting materials.
Likewise, German embryologist Hans Driesch had been studying the initial development of sea urchins, and in 1892, he found something odd: if one separates the cells of two-cell or four-cell embryos, those cells will become normal sea urchins and not 1/2 or 1/4 of a sea urchin. He was puzzled by this, and he came to the conclusion that this was the result of a "vital force". But he was one of the last mainstream biologists to support vitalism.
Vitalists could retreat into other territory, but they suffered numerous other defeats. And over the last century, the development of biochemistry and molecular biology elucidated metabolic pathways, genetic-information handling, etc. in great detail, with not a trace of "vital force" to be found. What makes living things alive was shown to be a matter of organization, not some special substance.
But as Dr. Isaac Asimov had once pointed out in one of his writings (according to my (LP) memory), there is something disappointing about the fall of vitalism. If a "vital force" exists, it would have to interact with nonliving matter, and its interactions could be used to detect it. And such a "life detector" would greatly simplify certain tasks, like detection of contamination by unwanted organisms and the search for life on other planets.
Related to vitalism is mind-body dualism, the theory that mind is due to some nonphysical "mind stuff". Although mental processes are not understood as well as life processes, mind-body dualism has proved as unsupportable as vitalism.
Turning to creationists, they do not appear to have any "official" stance on vitalism, and some, like Michael Behe, are apparently non-vitalists. They accept the discoveries of biochemistry and molecular biology about the structure of organisms, and they try to argue that those structures are unevolvable, on account of irreducible complexity or analogy with objects known to be designed or whatever. However, Jonathan Wells appears to have vitalist views of heredity and development.
