The only help against this is in the study by the presiding justice, not as lawyer but as psychologist, of the faces of the jury while the contending lawyers make their addresses. He must observe very narrowly and carefully every influence exercised by the speeches, which is irrelevant to the real problem, and then in summing up call it to the attention of the jury and bring them back to the proper point of view. The ability to do this is very marvelous, but it again is an exceedingly difficult performance.
Nowadays persuadability is hardly more studied but anybody who has empirically attained some proficiency in it has acquired the same tricks that are taught by theory. But these must be known if they are to be met effectively. Hence the study of the proper authors can not be too much recommended. Without considering the great authors of the classical period, especially Aristotle and Cicero, there are many modern ones who might be named.
The judgment to be discussed in the following section is not the judgment of the court but the more general judgment which occurs in any perception. If we pursue our tasks earnestly we draw from the simplest cases innumerable inferences and we receive as many inferences from those we examine. The correctness of our work depends upon the truth of both. I have already indicated how very much of the daily life passes as simple and invincible sense-perception even into the determination of a sentence, although it is often no more than a very complicated series of inferences each of which may involve a mistake even if the perception itself has been correct. The frequency with which an inference is made from sense-perception is the more astonishing inasmuch as it exceeds all that the general and otherwise valid law of laziness permits. In fact, it contradicts that law, though perhaps it may not do so, for a hasty inference from insufficient premises may be much more comfortable than more careful observation and study. Such hasty inference is made even with regard to the most insignificant things. In the course of an investigation we discover that we have been dealing only with inferences and that our work therefore has been for nothing. Then again, we miss that fact, and our results are false and their falsehood is rarely sought in these petty mistakes. So the witness may have “seen” a watch in such and such a place when in reality he has only heard a noise that he took for the ticking of a watch and hence _inferred_ that there had really been a watch, that he had seen it, and finally _believed_ that he had seen it. Another witness asserts that X has many chickens; as a matter of fact he has heard two chickens cluck and infers a large number. Still another has seen footprints of cattle and speaks of a herd, or he knows the exact time of a murder because at a given time he heard somebody sigh, etc. There would be little difficulty if people told us how they had inferred, for then a test by means of careful questions would be easy enough--but they do not tell, and when we examine ourselves we discover that we do exactly the same thing and often believe and assert that we have seen or heard or smelt or felt although we have only inferred these things.[153] Here belong all cases of correct or partly correct inference and of false inference from false sense-perception. I recall the oft-cited story in which a whole judicial commission smelt a disgusting odor while a coffin was being exhumed only to discover that it was empty. If the coffin, for one reason or another, had not been opened all those present would have taken oath that they had an indubitable perception although the latter was only inferred from its precedent condition.