3. Indeterminacy as Contingency. With the rise of
Newtonian physics and its development, Laplacian
determinism gained undisputed supremacy. Only in the
middle of the nineteenth century did it wane to some
extent. One of the earliest to regard contingent events
in physics—an event being contingent if its opposite
involves no contradiction—as physically possible was
A. A. Cournot (Cournot, 1851; 1861). Charles Re-
nouvier, following Cournot, questioned the strict va-
lidity of the causality principle as a regulative deter-
minant of physical processes (Renouvier, 1864). A
philosophy of nature based on contingency was pro-
posed by Émile Boutroux, who regarded rigorous
determinsim as expressed in scientific laws as an inade-
quate manifestation of a reality which in his opinion
is subject to radical contingency (Boutroux, 1874). The
rejection of classical determinism at the atomic level
played an important role also in Charles Sanders
Peirce's theory of tychism (Greek: tyche = chance)
according to which “chance is a basic factor in the
universe.” Deterministic or “necessitarian” philosophy
of nature, argued Peirce, cannot explain the undeniable
phenomena of growth and evolution. Another incon-
testable argument against deterministic mechanics was,
in his view, the incapability of the necessitarians to
prove their contention empirically by observation or
measurement. For how can experiment ever determine
an exact value of a continuous quantity, he asked, “with
a probable error absolutely nil?” Analyzing the process
of experimental observation, and anticipating thereby
an idea similar to Heisenberg's uncertainty principle,
Peirce arrived at the conclusion that absolute chance,
and not an indeterminacy originating merely from our
ignorance, is an irreducible factor in physical processes:
“Try to verify any law of nature, and you will find
that the more precise your observations, the more
certain they will be to show irregular departures from
the law. We are accustomed to ascribe these, and I
do not say wrongly, to errors of observation; yet we
cannot usually account for such errors in any anteced-
ently probable way. Trace their causes back far enough
and you will be forced to admit they are always due
to arbitrary determination, or chance” (Peirce, 1892).
The objection raised for instance by F. H. Bradley, that
the idea of chance events is an unintelligible concep-
tion, was rebutted by Peirce on the grounds that the
notion as such has nothing illogical in it; it becomes
unintelligible only on the assumption of a universal
determinism; but to assume such a determinism and
to deduce from it the nonexistence of chance would
be begging the question.