5. Immediate Consequences of the Entropy Con-
ception. Boltzmann's statistical interpretation of
entropy, based as it was on probabilistic considerations,
had to regard the principle of entropy increase as a
statistical law rather than as a strict law of nature as
originally maintained by thermodynamics. The con-
clusion that a spontaneous change toward a state of
smaller entropy or increased order, though extremely
improbable, is no longer an impossibility had, as we
shall see, important implications for the cosmological
applications of the concept of entropy.
The first to draw cosmological conclusions from
thermodynamics was, as we have seen, Thomson in
1852. Two years later, Helmholtz discussed the dissi-
pation principle and formulated the so-called “theory
of thermal death,” or “heat death” (Helmholtz, 1854).
Eventually, Helmholtz declared, the universe would
run down to a state of uniform temperature and “be
condemned to a state of eternal rest.” These arguments
by Thomson and Helmholtz implied also the existence
of an initial state of minimum entropy and hence a
distinctive beginning “which must have been produced
by other than the now acting causes”; they challenged
therefore uniformitarian geology (James Hutton,
Charles Lyell) and its denial of large-scale catastrophic
changes in the past. Since, moreover, the Darwinian
theory of biological evolution relied at that time con-
siderably on the uniformitarian doctrine, it was only
natural that the religious controversy about Darwinism
embraced also the discussion on entropy.
The principle of entropy increase was also carried
over into social philosophy, primarily by Herbert
Spencer. His First Principles (1862), published three
years after Darwin's Origin of Species and aimed at
interpreting life, mind, and society in terms of matter,
motion, and energy (force), had as its central thesis the
instability of homogeneity and its trend toward
heterogeneity as a characteristic of evolution in all its
phases, whether of individual organisms, groups of
organisms, the earth, the solar system, or the whole
universe. These developments, however, were held as
incidental to a more fundamental process, namely, “the
integration of matter and the concomitant dissipation
of motion” (Spencer, 1862). That Spencer's social
physicalism and its alleged implications for human
history had been directly influenced by the principle
of energy dissipation is shown by the fact that in the
fifth edition of
First Principles (1887) Spencer made
an explicit reference to Helmholtz' essay on “The
Interaction of Natural Forces.” Spencer's conclusion
that the total degradation of energy in the cosmos is
followed, due to a process of concentration under
gravitation, by a renewed dispersion and evolution so
that eras of dissolution and evolution alternate, found
but little approval by contemporary scientists like John
Tyndall and James Clerk Maxwell (Brush, 1967).
A most remarkable application of the notion of
entropy to history was made by Henry Adams. Trying
like others of his generation to establish history as a
science, and prompted by the conceptual similarity
between history and irreversibility, Adams attempted
to describe human history in terms of socio-physical
or rather socio-thermodynamical laws (Adams, 1919).
Stimulated by Andrew Gray's study of Lord Kelvin
(Samuels, 1964) and, in particular, by Gray's discussion
of the social implications of “Kelvin's great generaliza-
tion” (energy dissipation) and the idea of the ultimate
heat death which had been popularized meanwhile by
H. G. Wells in The Time Machine (1895), Adams re-
ferred to Auguste Comte's teachings that the human
mind had passed through three phases, the theological,
metaphysical, and positive; these phases Adams com-
pared with the chemical phases of solid, liquid, and
gaseous, subject to Gibbs's phase'rule, and claimed that
these “three phases always exist together in equilib-
rium; but their limits on either side are fixed by changes
of temperature and pressure, manifesting themselves
in changes of Direction or Form.” The Renaissance,
for example, with its marked change in direction, form,
and level of what Adams called “spiritual energy,” was
for him but a phase transition in accordance with
Gibbs's rule. Adams concluded that the future historian
“must seek his education in the world of mathematical
physics” and, in particular, in the teachings of Kelvin,
Maxwell, and Gibbs.
