The third and final reason why the sanction by force is necessary is the one to which Aristotle accords prime importance. The whole social organization for making and enforcing the law would be superfluous, he argues, if men would act in accordance with true order without compulsion or the threat of compulsion. If men were motivated always by the aidos, piety or shame, to refrain from doing what is wrong and shameful, what defiles their stature as men; or if, in the case of possible lapse, admonitions by fellowmen would be sufficient to make the potential wrongdoer aware of what he is doing and shame him into right conduct; then there would be no need for the law and its enforcement as the organization of society for maintaining its order.
But that is not the nature of man. To be sure, it is the nature of man to be a person, that is, to order his conduct by reason and conscience. But it is also the nature of man not to be a person. In the first place, man does not spring into the world as a full-grown person but is born as a child. His personality is a structure in the soul that grows slowly and hardly achieves maturity before the age of thirty. With some it takes longer. A large proportion of men never reach full personal stature, and sometimes their growth stops very early.
For the full-grown man, Aristotle uses the term spoudaios, the mature man—but when he speaks about the possibility of realizing a true order in the Hellenic polis, he remarks that probably in no Greek polis could be found even one hundred mature men who could form the nucleus of an adequate ruling group. Besides the children who lack the full development of personality, there are in every society "slaves by nature," that is, men who, for one reason or another, never grow to maturity but need social pressures, energetic reminders, and ultimately the threat of force to keep them on the straight path.
They still may be useful members of society by virtue of their special skills; but they are not the members who can let the substance of order that lives in man flow into the order of society and thereby sustain it, for too little of that substance lives in them.
Contemporary social scientists have observed the same human types as Aristotle and speak of them as the inward-directed and outward-directed personalities—language that may become ontologically misleading, since the point is precisely that the outward-directed personalities are so directed because they are deficient in personality.