Dr. Goring is led to the conclusion that there is not any significant relationship between crime and what are popularly believed to be its "causes", and that crime is only to a trifling extent the product of social inequalities or adverse environment, and that there are no physical, mental, or moral characteristics peculiar to the inmates of English Prisons: that one of the principal determinants of crime is "mental defectiveness," and as this is a heritable condition, the genesis of crime must to this extent be influenced by heredity. Putting aside the part played by the different circumstances affecting criminal man, biologically and otherwise, and without subscribing to the different views and doctrines which, in the opinion of the author, result from the inquiry, the broad and general truth which appears from this mass of figures and calculations is that the "criminal" man is, to a large extent, a "defective" man, either physically or mentally, or, is unable to acquire the complex characters which are essential to the average man and so is prone to follow the line of least resistance. This truth may not be new or startling. It is advanced now by Dr. Goring as a truth which is scientifically demonstrable and so commanding respect and possessing a value which would not belong to statements based on purely empirical observation. This result may be regarded as modest and even disproportionate to the labour involved, but it is worthy of attainment, for much is gained everywhere and especially in the realm of penology, when definite ideas as to the nature of the problems dealt with are substituted for vague notions, or even illusions, as to the nature of the criminal: notions which, in the absence of detached and scientific inquiry, undertaken, as this has been, from a single-minded desire to search out what is true, may have their origin in two quite contrary sources, _viz._: an undue pity for the offender or an undue desire to be revenged on him. Quite apart from general incapacity to live up to the required social level which brings them within the meshes of the criminal law, Dr. Goring even suggests that the physical aptitude of evading the police may affect statistics, and the fact is that the weaker and not the stronger man is "run in," although the "criminal diathesis" may be equally strong in each. In any case his conclusion on this point is very emphatic, _viz._: that English criminals are selected by their physical condition, and that the one significant physical association with criminality is a generally defective physique; and that the one vital mental constitutional factor in the etiology of crime is defective intelligence.