In the application of law, and more particularly in the application of the criminal law, "to prove" means "to produce evidence of facts which occurred in the past." The application of law implies also the proof of all sorts of abstract theories, but by "proof" in the application of law one must only include proof of concrete facts. The particular character of proof in criminal cases lies in the fact that such proof is of a legal nature. Starting from the principle that absolute certainty cannot be achieved, one cannot avoid the question of what is the degree of certainty required in criminal cases. The answer to this question is extremely difficult. One can give only an approximate answer. Besides, it will not necessarily be the same for all types of proof in criminal cases. But in each case the answer is of a judicial nature.
W. P. J. Pompe,
Proof in (Civil Law) Criminal Procedure,
43 Neb. L. Rev. 51
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