Let me give illustrations to bring into view the characteristics of a strong and of a weak will. Great inventors, great statesmen, great reformers, illustrate strength of will. We note in them especially tenacity of purpose and a marvelous faculty for adjusting and readjusting means to ends. Persons who are swayed by the sensual appetites illustrate weakness of will. We note in them vacillation of purpose, and the power of adjusting means to ends only in its rudimentary form. The ideas of virtue are complex. No one can illustrate virtue on a high plane unless he is capable of holding in mind long trains and complex groups of ideas. The lowest vices, on the other hand, are distinguished by the circumstance that the ends to which they look are simple, and the means employed often of the crudest kind. Thus, suppose that a person of weak will is hungry. He knows that gold will buy food. He adopts the readiest way to get gold. Incapable of that long and complex method of attaining his end, which is exhibited, for instance, by the farmer who breaks the soil, plants the corn, watches his crops, and systematizes his labors from the year's beginning to its end, he takes the shortest road toward the possession of gold--he stretches forth his hand and takes it where he finds it. The man of weak will, who has a grudge against his rival, is not capable of putting forth a sustained and complex series of efforts toward obtaining satisfaction, for instance, by laboring arduously to outstrip his rival. He is, furthermore, incapable of those larger considerations, those complex groups of ideas relating to society and its permanent interests, which check the angry passions in the educated. He gives free and immediate rein to the passion as it rises. He takes the readiest means of getting satisfaction: he draws the knife and kills. The man of weak will, who burns with sensual desire, assaults the object of his desire. The virtues depend in no small degree on the power of serial and complex thinking. Those vices which are due to weakness of will are characterized by the crudeness of the aim and the crudeness of the means. To strengthen the will, therefore, it is necessary to give to the person of weak will the power to think connectedly, and especially to reach an end by long and complex trains of means. Let us pause here for a moment to elucidate this point by briefly considering a type of criminality which is familiar to all guardians of delinquent children. This type is marked by a group of salient traits, which may be roughly described as follows: Mental incoherency is the first. The thoughts of the child are, as it were, slippery, tending to glide past one another without mutual attachments. A second trait is indolence. A third, deficiency in the sense of shame; to which may be added that the severest punishments fail to act as deterrents.