Adapted from Criminal Psychology: A Manual for Judges, Practitioners, and Students by Hans Gross (1911)

It is a mistake to suppose that it is enough in most cases to study that side of a person that is at the moment important—his or her dishonesty only, his or her laziness, etc. That will naturally lead to merely one-sided judgment and anyway be much harder than keeping the whole person in eye and studying him or her as an entirety. Every individual quality is merely a symptom of a whole nature and can be explained only by the whole complex; the good properties depend as much on the bad ones as the bad on the good ones. At the very least, the quality and quantity of a good or bad characteristic shows the influence of all the other good and bad characteristics. Kindliness is influenced and partly created through weakness, indetermination, too great susceptibility, a minimum acuteness, false constructiveness, untrained capacity for inference; in the same way, again, the most cruel hardness depends on properties which, taken in themselves, are good: determination, energy, purposeful action, clear conception of one's fellows, healthy egotism, etc. Every person is the result of his or her nature and nurture, i.e. of countless individual conditions, and every one of his or her expressions, again, is the result of all of these conditions. If, therefore, he or she is to be judged, he or she must be judged in the light of them all.

For this reason, all those indications that show us the person as a whole are for us the most important, but also those others are valuable which show him or her up on one side only; however, in the latter case, they are to be considered only as an index that never relieves us from the need further to study the nature of our subject.

We ask, for example, what kind of person will give us the best and most reliable information about the conduct and activity, the nature and character, of an individual? We are told: that sort of person who is usually asked for the information—his or her nearest friends and acquaintances and the authorities. Before all of these people do not show themselves as they are because the most honest will show themselves before people in whose judgment they have an interest at least as good as, if not better than they are—that is fundamental to the general egoistic essence of humanity, which seeks at least to avoid reducing its present welfare. Authorities who are asked to make a statement concerning any person can say reliably only how often the individual was punished or came otherwise in contact with the law or themselves. But concerning the individual's social characteristics the authorities have nothing to say; the detectives have to bring an answer. Then the detectives are, at most, simply people who have had the opportunity to watch and interrogate the servants, house-furnishers, porters, and corner-loafers, and other people in the employ of the individual. Why we do not question these people ourselves I cannot say; if we did, we might know these people on whom we depend for important information and might put our questions according to the answers that we need. 

It is a purely negative thing that an official declaration is nowadays not infrequently presented to us in the disgusting form of gossip. But in itself, the form of getting information about people through those who work for them is correct. People show their weaknesses most readily before those whom they hold of no account. This fact is well-known, but not sufficiently studied. It is of considerable importance. The Styrian, Peter Rosegger, one of the best students of mankind, once told a first-rate story of how the most intimate secrets of certain people became common talk although all concerned assured him that nobody had succeeded in getting knowledge of them. The news-agent was finally discovered in the person of an old, quiet woman who worked by the day in various homes and had found a place, unobserved and apparently indifferent, in the corner of the sitting-room. Nobody had told her any secrets, but things were allowed to occur before her from which she might guess and put them together. Nobody had watched this disinterested, ancient lady; she worked like a machine; her thoughts, when she noted a quarrel or anxiety or disagreement or joy, were indifferent to all concerned, and so she discovered a great deal that was kept secret from people perceived to be more important. This simple story is very significant—we are not to pay attention to gossips but to keep in mind that the information of people is in the rule more important and more reliable when the question under consideration is indifferent to them than when it is important.