The place of probability in the positive determination of the order of modern criminal procedure is not insignificant. When the law determines upon a definite number of jurymen or judges, it is probable that this number is sufficient for the discovery of the truth. The system of prosecution establishes as a probability that the accused is the criminal. The idea of time-lapse assumes the probability that after the passage of a certain time punishment becomes illusory, and prosecution uncertain and difficult. The institution of experts depends on the probability that the latter make no mistakes. The warrant for arrest depends on the probability that the accused behaved suspiciously or spoke of his crime, etc. The oath of the witness depends on the probability that the witness will be more likely to tell the truth under oath, etc. Modern criminal procedure involves not only probabilities but also various types of possibility. Every appeal has for its foundation the possibility of an incorrect judgment; the exclusion of certain court officials is based on the possibility of prejudice, or at least on the suspicion of prejudice; the publicity of the trial is meant to prevent the possibility of incorrectness; the revision of a trial depends on the possibility that even legal sentences may be false, and the institution of the defendant lawyer depends upon the possibility that a person without defense may receive injustice. All the formalities of the action of the court assume the possibility that without them improprieties may occur, and the institution of seizing letters and messages for evidence, asserts only the possibility that the latter contain things of importance, etc. When the positive dicta of the law deal with possibility and probability in questions of great importance the latter become especially significant.