Does heredity account for one quality more than another?-- Impossibility of forecasting the conduct of others--Do criminals breed criminals?--The fit and the unfit--Unequal endowments--Ability and position--Inherited faculties and social pressure--Crime the result of wrongly directed powers--Original sin and heredity--Heredity behind everything. In the effort to assign a general cause for criminality an undue emphasis may easily be placed on any one factor. There are those who seem to think that heredity is the main cause, but they rarely attempt to define the content of the term. In a sense heredity is the cause of everything, but in that case it cannot be held to be the cause of one thing more than of another. Suppose a man becomes insane at the age of thirty and it is shown that a number of his relatives, direct and collateral, have also been insane. If heredity accounts for his insanity what will account for his sanity? Such a man under treatment may recover, but sane or insane his heredity is not altered. The fact is that we none of us know enough regarding the qualities of our ancestors to be justified in imputing our inheritance of any special tendency to any particular one of them, and every successive generation implies a mixing, if not a blending, of very complex and sometimes opposing qualities. If a man knows anything about anybody in this world surely it is about himself. His knowledge is incomplete, but it is more full and varied than his knowledge of any other body. He may be expected to know something about the qualities and faculties of his wife. Yet all he knows of himself and her, added to all he knows of the laws of heredity, does not enable him to forecast with any degree of accuracy the faculties and tendencies of his infant child, or to trace these back when they have developed. In the case of criminals born and brought up in hotbeds of vice it is even more hopeless to trace back family history, because there is often in their case a grave uncertainty as to the personality of the male parent. To say that as wolves breed wolves criminals breed criminals is nonsense and mischievous nonsense. As canaries breed canaries do poets breed poets? Criminals are men and women who have gone wrong; not necessarily because of the possession of certain powers which they have inherited, but because these powers have been used in a wrong direction. They come from all classes; and there is nothing to show that if their children were taken from them early in life and brought up in favourable surroundings they would take to crime; but there is an abundance of evidence on the other side.