This “service” was his trenchant attack on the concept of “vital force” [Lebenskraft], widely held, by a variety of thinkers of differing orientations, to have struck the decisive blow (cf. Gregory, 1977, pp. 131f).
Lotze’s medical dissertation was, under one description, his opening salvo in this attack, for in it he advocated the abandonment of key concepts of Naturphilosophie including, inter alia, “polarity” and “vital oscillation” (cf. Woodward & Pester, 1994, p. 167 and Pester, 1997, p.58).
But his targets also included the diagnostic terminology favored by the medical nosology of the day—most prominently, “asthenia” (and its cognate notions) and, as already mentioned, “vital force.”
While the former was a contribution of the Brunonian theory, further elaborated in Germany by numerous (and peculiar) enthusiasts, the latter was a more widespread assumption of biological thought generally speaking.
Yet despite such important differences, both might be pegged with the same fundamental flaw:
both could be characterized as empty “abstractions” that falsely paraded as causally “explanatory” notions.
Put in Kantian terms, they were both treated (wrongly) as though they were truly “constitutive” principles of human cognition.
Teleology, and teleological notions generally, while licit for certain heuristic purposes, pace Kant, cannot be raised to the level of cognitive principle.
«<Hence, while enquiries into the biological realm may safely assume purposive function, as a necessary theoretical posit, such assumptions may serve only as regulative—not constitutive—principles in biological thought.»> [NB]
«<Teleological notions, such as ‘order’ and ‘purpose’, are, as necessary presuppositions of our theorization generally, ineliminable.»>
But such notions cannot be used explanatorily or, more precisely, in a way that effectively precludes further investigation into the actual causes of organic phenomena.
In other words, from the perspective of scientific explanation itself, vital force has no role to play.