“Vitalism” is primarily a metaphysical doctrine concerning the nature of living organisms, although it has been generalized, by Henri Bergson for example, into a comprehensive metaphysics applicable to all phenomena. We shall examine vitalism only as a theory of life.
There have been three general answers to the question “What distinguishes living from nonliving things?” The first, and currently most fashionable, answer is “A complex pattern of organization in which each element of the pattern is itself a nonliving entity.”
In this view, a living organism, and each of its living parts, is exhaustively composed of inanimate parts; and these parts have no relations except those that are also exhibited in inanimate systems. The second answer is “The presence in living systems of emergent properties, contingent upon the organization of inanimate parts but not reducible to them.”
This answer resembles the first in acknowledging that a living system is exhaustively composed of nonliving parts; it holds, however, that the parts have relations in the living system that are never exhibited in inanimate systems. The third, and least fashionable, answer is “The presence in living systems of a substantial entity that imparts to the system powers possessed by no inanimate body.”
This is the position of vitalism. It holds, first, that in every living organism there is an entity that is not exhaustively composed of inanimate parts and, second, that the activities characteristic of living organisms are due, in some sense, to the activities of this entity.
The Vital Entity
The vital entity that animates an organism may, for brevity, be termed its “Life”—a usage that is in fact supported by vitalistic writings. The first thesis of vitalism may be stated as: The Life of an organism is substantial, but it is not—or at least not totally—made up of nonliving substance.
|nature of substance|
To say that the Life is substantial is to indicate that it has always been conceived more or less closely in accordance with an available doctrine concerning the nature of substance. All vitalists have, for example, held that the Life of an organism is a particular, not a universal; that it is the subject of predicates and not only a predicate; and that it is an agent possessing some degree of autonomy with respect to the body it animates. Most, but not all, vitalists have also maintained that Life, or at least an aspect of it, is capable of existence apart from its organism.
In addition to regarding Life as a substance, all vitalists have adopted a model that helps to specify the sort of substance it is. It may be helpful at this point to distinguish between naive and critical vitalism. Naive vitalism is embedded in common sense in much the same way as a version of mind-body dualism: everyday speech, common maxims, and habitual metaphors all suggest and support it.
This type of vitalism, for example, is simply the most direct and literal interpretation of such expressions as “He lost his life,”“a lifeless corpse,”“A cat has nine lives,” and “Scientists will someday create life in the test tube.”
|nature of life|
When the average man thinks about the nature of life at all, he is likely to be guided by these and similar expressions.Naive vitalism has been and indeed still is the popular doctrine. The model of Life adopted by the naive vitalist is the most familiar one available; Life is regarded as a material substance, usually as a fluid body.
In the most primitive forms of vitalism, the Life is flatly identified with a material fluid, the breath, or the blood. This view just misses materialism; it is vitalistic only because the fluid is assigned properties unlike those of any other material body, for example, the power of sensation. Slightly less primitive is the view that Life is a fluid like the blood, only invisible and rather more fiery.
The doctrine of the spirits as it occurs in Galen and his successors is an example of this sort of vitalism. The process of etherealizing the Life culminates in the view that it is a fluid but one that is assigned no properties other than its power of animating an organism. This is still a prevalent view and was present, for example, in Mary Shelley’s Frankenstein.
Although it has conceptual and historical roots in the material substance models, critical vitalism is far more sophisticated. Its various versions have been elaborated by professional philosophers and biologists; indeed, its two outstanding exponents, Aristotle and the twentieth-century biologist and philosopher Hans Driesch, were professionals in both fields. Aristotle’s writings, especially his treatises On the Soul and On the Generation of Animals, are the standard works of vitalistic doctrine.
In them Aristotle established four traditions that, it can be said, virtually determined the course of subsequent critical vitalism: he identifies what has been called here the Life of an organism with its psyche; he locates purposive activity, organic unity, and embryological development as the phenomena that vitalism must take most seriously; he argues that the activities of the part must be understood by reference to the form of the whole and that morphogenesis must be understood by reference to the form of the adult; and finally, he describes the manner of the psyche’s influence on its organism as formal, not efficient, causation. In short, critical vitalism after Aristotle takes the soul as the model of the Life and attributes to Life the power of achieving and maintaining organic form.
NATURE AND HISTORY. Vitalism was defined above as a metaphysical doctrine in the sense that it is formulated with a degree of vagueness sufficient to exempt it from empirical refutation. However, this is not to say that vitalism has no implications concerning matters of fact.
By means of very plausible arguments, vitalists have derived empirical consequences, some of which have been falsified and some verified. For example, it was argued that since the Life is the blood, a transfusion of blood into a corpse would bring it to life.
This experiment failed, but the failure obviously did not refute every version of vitalism or even the doctrine that the Life is the blood. More seriously, Driesch argued that if vitalism is true, then a bit of embryonic tissue that ordinarily develops into a particular organ ought to be capable of developing into other organs.
It does happen that some embryonic tissue has this capability. But although Driesch cites such an experiment, he did not actually predict its results. Had they been unfavorable, Driesch would still have had a way to save vitalism. For although he is willing to set limits to the regulative powers of the Life, he gives no antecedent specification of these limits.
In short, vitalism is irrefutable.When this is coupled with the tendency to describe the Life in terms that are among the most problematical in philosophy, it is easy to see that vitalism is subject to the worst aspects of intellectual obscurantism.
Its leading exponents, for instance, William Harvey, Georg Stahl, G. L. L. Buffon, Caspar Wolff, J. F. Blumenbach, Lorenz Oken, and K. E. von Baer, represent no improvement upon Aristotle either in the philosophical elaboration of vitalism or in its application to biological phenomena.
|Aristotle to Driesch|
The long period from Aristotle to Driesch, on the contrary, was characterized by confused invasions of naive vitalism; by the proliferation of such ad hoc entities as life forces, formative impulses, generative fluids, animal heat, and animal electricity; and by the merging of vitalistic thought with other fragments of biological metaphysics, such as the doctrine that living things are arranged along a linear scale corresponding to degrees of perfection (the scala naturae), and the archetypal conceptions of organic form.
Moreover, vitalism showed a curious tendency to come out on the losing side of biological controversy: After Charles Darwin, it was anti-Darwinian; and it supported the view that organic syntheses could be effected only in a living organism. It also supported the useless and misleading conception of a primordial living substance, the protoplasm, a term and idea that unfortunately still survive.
HANS DRIESCH. After Bergson, Hans Driesch is the best-known twentieth-century vitalist. (Bergson will not be considered here since his biological views are intelligible only as an application of his more general metaphysics.) Driesch’s position may be described as Aristotelianism painstakingly applied to modern findings—some of them the result of his own laboratory researches—in physiology and embryology. He also provides three empirical proofs of vitalism.
Driesch defines vitalism as “the theory of the autonomy of the processes of life.” It is doubtful that this rules out any biological theories at all, but it does locate Driesch’s major concern. He explicitly distinguishes between vitalism and animism, but he does not define animism. The term seems to be roughly equivalent to naive vitalism.
He also considers vitalistic the view that the parts of an organic system can be understood only by reference to the form of the whole—a view that might preferably be classified as “organismic.” But the latter distinction had not been clearly drawn in Driesch’s time; he is quite correct in assuming that organismic biology is closer to the vitalistic tradition than, for example, Cartesian mechanism is.
According to Driesch, the Life of an organism is a substantial entity, an entelechy. Driesch employs this term as a mark of respect for Aristotle, although he does not use it with Aristotle’s meaning. For Driesch, the entelechy is an autonomous, mindlike, nonspatial entity that exercises control over the course of organic processes; it is not actuality or activity in Aristotle’s sense.
Driesch admits that the laws of physics and chemistry apply to organic changes. There is even a sense in which everything that happens in the organism is subject to physicochemical explanation. We may consider, for example, the first division of a fertilized ovum into two blastomeres (daughter cells).
Even this relatively simple event can be analyzed as a complex sequence of cooperating chemical syntheses and mechanical movements resulting in, among other things, the duplication of the nucleus, the migration of the daughter nuclei into the opposite sides of the egg, and the formation of a cell membrane between them. Each step in each sequence is a physicochemical event and could be, at least in principle, described and explained as such.
But chemistry and physics cannot explain why the steps occur when and where they do. Thus—and on this point some interpretation is necessary—although each event that constitutes first cleavage is physicochemical, it is subject only to post hoc explanation in physicochemical terms. The state of the egg and its environment at time t does not determine what events will begin at later time t + dt.
|range of possibilities|
But the latter events, after they have occurred, can be exhibited as consequences of events that ended at t. The state of the egg at t determines a range of possibilities; the entelechy influences the course of cleavage, in Driesch’s terms, selectively “suspending” and “relaxing the suspension” of these possibilities.
An analogy may shed some light on this doctrine. Suppose that a person’s voluntary acts are undetermined, at least at the physicochemical level; that for example, whether or not I clench my fist is not decided by the laws of physics and chemistry. Then the constitution of my body at a given time presents two possibilities, both within my organic capacity: to clench my fist or not.
My choice to clench it is analogous to the action of an entelechy. The clenching could not by hypothesis have been predicted on physicochemical grounds, but after its occurrence it can be explained as the outcome of a sequence of physical and chemical events.
Driesch conceives of the laws of nature as placing constraints on the possible activities of a system. For example, the first principle of energetics (thermodynamics) states simply that whatever happens, energy is conserved, but conservation of energy is compatible with any number of actual changes in the system.
The entelechy operates in the region of possibilities left open by the operation of laws. Driesch favors a particular metaphor: the entelechy is like an artist who gives form to a material medium, the medium itself both providing possibilities and presenting limitations.