VITALISM. — In a very broad sense, it comprises the scientific and philosophical doctrines that affirm the irreducibility (both from an ontological and an epistemological standpoint) of biological phenomena to mechanical or physico-chemical phenomena, as advocated, for example, by J. Loeb (cf. *La conception mécanique*, French trans., Paris 1911, pp. 1-5), who extends the theory of “tropisms” to animals and humans. In this sense, ARISTOTLE, H.-L. BERGSON, H. DRIESCH, and N. HARTMANN are vitalists.
In a narrower sense, vitalism comprises a series of doctrines that extend from the 16th to the 19th century (whose principal stages are marked by the names of PARACELSUS, STAHL, BARTHEZ, and the Montpellier school), which posit a principle distinct from these phenomena to ensure their coordination: a vital principle assimilable to a spiritual principle called “arché” and radically distinct from the thinking soul (Montpellier school).
In a strict sense, vitalism today (under the current denomination of “neo-vitalism”) comprises scientific or philosophical conceptions that, after the end of the 19th century, in reaction to mechanistic conceptions of life and with reference to the positive data of biological sciences (particularly embryology), uphold the irreducibility of the vital to mechanism or to physico-chemical fact, both from an objective standpoint (in the realist or Kantian sense of the term) and from a subjective one.
Hence the distinction between methodological vitalism and doctrinal vitalism. The former is represented, for example, by REINKE, who, reviving Kant’s idea of the “regulative concept,” grants the concepts of “regulative forces” (*Die physischen Kräfte*) only the value of a “provisional concept” (*provisorischer Begriff*), useful, indeed necessary, insofar as life has not been created by laboratory means, but which leaves open the possibility of a further reduction either to material forces or to psychic ones, and thus reduces to an “as if” (*Als ob*, cf. J. REINKE, *Leblos u. Lebendig*, in *Kantstudien*, 31 [1926], esp. pp. 205 ff.). Doctrinal vitalism, on the other hand, maintains that organic finalism is a truly constitutive character, both in the sense of Kant’s a priori (as in H. DRIESCH, *Kant und das Ganze*, in *Kantstudien*, 29 [1924], pp. 365-67) and in a more immediately realist sense (as in R. RUYER, *Éléments de bio-psychologie*, Paris 1946; id., *Néo-finalisme*, 1912).
Organic finalism, by virtue of which the living being evolves through its internal forces from the embryonic state to adulthood and is truly a cause of itself, and which DRIESCH opposes both to descriptive or regulative finality and to static finality (that of machines) (cf. *Storia e dottrina del v.*, Italian trans., Naples 1912, pp. 1-13), has a twofold aspect: harmony (causal, compositional, and functional) and regulation, whether merely adaptive or regenerative to the embryonic stage (e.g., in sea urchins), which led DRIESCH to elaborate the technical concepts (which he opposes to collective concepts, ibid., pp. 244-49) of “prospective significance” (*prospektive Bedeutung*) and “prospective potency” (*prospektive Potenz*). The former expresses the actual, real destiny and is the normal aptitude of each blastema to produce a determined organ; the latter is the aptitude, common to all blastemas, to regenerate, in cases of disturbance or artificially induced division, the entirety of the organism (ibid., p. 271 ff.). While the first, capable according to various locations of producing a determined organism, is variable and susceptible of being represented by the formula S = f (a, g, E), where S signifies the *prospektive Bedeutung*, a the situation of the plasme in relation to an original pole, g the absolute magnitude of the system, and E a constant embracing the original capacity of the elementary organ within the specific limits of the morphogenetic system and its harmony with the other parts (ibid., pp. 295-98), the second is constant, at least at the initial stage, equal in all blastemas, which thus constitute a harmonic equipotential system (ibid., p. 420, note 255). Reflecting on these facts elaborated into technical concepts, DRIESCH observes that they are irreducible to an explanation by means of internal factors of an exclusively physico-chemical-mechanical nature (no part of a mechanical system can, of course, regenerate the entirety of the system, which presupposes the spatial presence in a single part of all the others [ibid., pp. 299 ff.]). Hence the appeal to a factor that transcends the physico-chemical order, the factor E, which, with reference to ARISTOTLE, DRIESCH calls “entelechy” (ibid., pp. 300-304), but in a new sense that he attempts to determine with a comprehensive reference to Kant’s categories of relation, causality, and substance, and ultimately to the constitutive category of individuability.
DRIESCH’s vitalism has been criticized both from a scholastic standpoint, because his entelechy is not the *entelechy* of ARISTOTLE (cf. H. NUYENS, *Évolution de la psychologie d’Aristote*, Louvain 1948, pp. 73-78), and from a scientific (cf. J. MATISSE, *Le rameau vivant du monde*, Paris 1945, pp. 77-91) and philosophical standpoint (cf. RUYER, *Éléments*, pp. 92-93), which objects to the entelechy of interspecific grafts, incomprehensible in DRIESCH’s position, and substitutes for the factor E the psychological notions of potential, thematic, and significant form, of structure, and of unitary domain (ibid., pp. 134 and 232 ff.; also *Néo-finalisme*, pp. 269-70).
It should be noted, however, that if one distinguishes in DRIESCH’s theory the experimental facts, the technical concepts, and the explanatory concepts of a philosophical nature, it is not necessary to tie the fate of the first two to the last. The experimental facts, in fact, have led to a clear distinction between mosaic eggs (e.g., mollusks) and totipotent or self-regulating eggs (e.g., sea urchins), also taking into account the characteristic anisotropy of all germs (cf. C. BOUNOURE, *L’autonomie de l’être vivant*, Paris 1949, pp. 16-38); but these additions do not in any way destroy, indeed they confirm, the incontestably experimental and operational value of the technical concepts. These allow the philosopher to construct a conception of the organism more adequate to the facts, thus avoiding the confusion between efficiency and form and the pretended autonomy of the “entelechy” with respect to the organism in the DRIESCHian conception, and inasmuch as it posits the soul in the organism as the form of matter according to the presuppositions of ARISTOTELIAN philosophy.