Conservation and Innovation : Helmholtz's Struggle with Energy ...

other seven eighths are lost in the form of heat: "the human body is a better
machine than the steam engine, only its fuel is more expensive than the fuel of
steam engines" 331. But despite the fact that we cannot yet prove that the work
produced by living bodies is a total equivalent of the chemical forces which have
been set into action, still "I think we may consider it as extremely probable that
the law of the conservation of force holds good for living bodies" 332. Finally the
"vital principle" is disregarded, in that, if there is complete conservation of force,
the physical forces in the living body cannot be removed and again set in action
at any moment by the influence of the vital principle. In fact conservation of force
can exist only in those systems in which the forces in action (like all the forces of
inorganic nature) have always the same intensity and direction if the
circumstances under which they act are the same.
Indeed Helmholtz can claim that in a few years the principle has
completely modified the view of life phenomena, and that a general unified
approach to physical, cosmological and physiological phenomena has been
achieved.
In November 1862 Helmholtz became Pro-Rector of Heidelberg
University and on this occasion delivered a talk on "The Relation of Natural
Sciences to Science in General" 333. After analysing the differences of the Kantian
epistemological approach and that of Schelling and Hegel, Helmholtz recalls and
expands some of the ideas already expressed in the Introduction to the 1847
Erhaltung. Natural science cannot be satisfied with a collection of facts: it
requires the law that rules them and the corresponding causes. There is a
difference between artistic and logical induction : free will implies the
impossibility of reducing our psychological expressions to a rigid law. One of the
deep differences between natural sciences and human sciences is exactly this :
the former can attain quite general rules and laws , the latter judge on the basis
of a psychological sensibility. Human sciences cannot unify observations and
331 Helmholtz "Organic Nature" p.
332 Ibidem
333 Helmholtz, Hermann. "Ueber das Verhältniss der Naturwissenschaften zur
Gesammtheit der Wissenschaften". Rectoratsrede. Heidelberger Universitätsprogramm 1862.
Rep. in Populäre Wissenschaftliche Vorträge 1st vol. Braunschweig: Vieweg, 1865 (and
following editions); translated in English as "On the relation of the physical sciences to science
in general" in the Annual Report of the Smithsonian Institution for the year 1871, p.217-234;
reproduced in PL 1873 (and following editions); also in R.Kahl SW.