The making of a confession, according to laymen, ends the matter, but really, the judge’s work begins with it. As a matter of caution all statutes approve confessions as evidence only when they agree completely with the other evidence. Confession is a means of proof, and not proof. Some objective, evidentially concurrent support and confirmation of the confession is required. But the same legal requirement necessitates that the value of the concurrent evidence shall depend on its having been arrived at and established independently. The existence of a confession contains powerful suggestive influences for judge, witness, expert, for all concerned in the case. If a confession is made, all that is perceived in the case may be seen in the light of it, and experience teaches well enough how that alters the situation. There is so strong an inclination to pigeon-hole and adapt everything perceived in some given explanation, that the explanation is strained after, and facts are squeezed and trimmed until they fit easily. It is a remarkable phenomenon, confirmable by all observers, that all our perceptions are at first soft and plastic and easily take form according to the shape of their predecessors. They become stiff and inflexible only when we have had them for some time, and have permitted them to reach an equilibrium. If, then, observations are made in accord with certain notions, the plastic material is easily molded, excrescences and unevenness are squeezed away, lacunæ are filled up, and if it is at all possible, the adaptation is completed easily. Then, if a new and quite different notion arises in us, the alteration of the observed material occurs as easily again, and only long afterwards, when the observation has hardened, do fresh alterations fail. This is a matter of daily experience, in our professional as well as in our ordinary affairs. We hear of a certain crime and consider the earliest data. For one reason or another we begin to suspect A as the criminal. The result of an examination of the premises is applied in each detail to this proposition. It fits. So does the autopsy, so do the depositions of the witnesses. Everything fits. There have indeed been difficulties, but they have been set aside, they are attributed to inaccurate observation and the like,--the point is,--that the evidence is against A. Now, suppose that soon after B confesses the crime; this event is so significant that it sets aside at once all the earlier reasons for suspecting A, and the theory of the crime involves B. Naturally the whole material must now be applied to B, and in spite of the fact that it at first fitted A, it does now fit B. Here again difficulties arise, but they are to be set aside just as before.