The famous lecture given by
Niels Bohr in
1932 that was republished in
Nature in 1933. The lecture covered his ideas on the correlations between
quantum physics, concepts in
biology and
evolution, and even some insights into the nature of
psychology and
psychoanalysis. He made the suggestion that life must be taken as an
axiom inasmuch as we take the quantum of action in quantum theory as an
axiom. Bohr, best known for his work in quantum physics, was the son of a biologist and maintained a strong interest in living systems, the simplest of which, he believed, was so much more complex than the most complex of non-living matter. He was inspired by and, in turn, inspired many of his colleagues, including,
Max Delbruck and
Schrodinger.
Extended quotes:
"If (..) we were able to push the analysis of the mechanism of living organisms as far as that of atomic phenomena, we should not expect to find any features foreign to inorganic matter. In this dilemma it must be kept in mind, however, that the conditions in biological and physical research are not directly comparable, since the necessity of keeping the object of investigation alive imposes a restriction to the former which finds no counterpart in the latter. Thus, we should doubtless kill an animal if we tried to carry the investigation of its organs so far that we could tell the part played by the single atoms in vital functions. In every experiment on living organisms there must remain some ucertainty as regards the physical conditions to which they are subjected, and the idea suggests itself that the minimal freedom we must allow an organism will be just large enough to permit it, so to say, to hide its ultimate secrets from us. On this view, the very existence of life in biology be considered as an elementary fact, just as in atomic physics the existence of the quantum of action has to be taken as a basic fact that cannot be derived from ordinary mechanical physics" ("Light and Life" Nature 131, 421-423 & 457-459/1933).
"It is impossible, from our standpoint, to attach an unambiguous meaning to the view sometimes expressed that the probability of the occurrence of certain atomic processes in the body might be under the direct influence of the will.(...)The freedom of the will is to be considered as a feature of conscious life which corresponds to functions of the organism that not only evade a causal mechanical description but resist even a physical analysis carried to the extend required for an unambiguous applicatio of the statistical laws of atomic mechanics" (ibidem).
HIs follow up article, "Light and Life, Revisited", was published posthumously in Nature in 1956.