Now it is evident that adaptation on the part of individuals and groups to the requirements of life may be in part accomplished by biological selection, that is, by eliminating the least adapted. But selection is, after all, a very clumsy and imperfect instrument for securing the highest type of adaptation. Again, it is evident that a certain degree of adaptation can be secured through the constraint of government and law; but only a relatively low type of adaptation can be secured in such an external way. It is finally evident, therefore, that the highest type of adaptation in either individual or social life can be secured only by training the intelligence and moral character of individuals so that they will be sufficient to meet the requirements of existence. Another feature of social progress which we have not yet mentioned in this chapter, though we have noted it repeatedly in earlier chapters, is the increased complexity of social organization. This increased complexity is in part due to the mere increase in numbers. It is also due to the various processes themselves by which wider and more universal adaptation is brought about in society. Thus, while every useful mechanical invention aids man to conquer nature, it at the same time increases the complexity of social life. Now in a more complex society there is more opportunity for conflicts of habit between individuals, more opportunity for social maladjustment, and therefore more opportunity for the failure of some part or all of the group in achieving a social life characterized by harmony, efficiency, and capacity for survival. Hence, the adaptation of individuals in the large and complex groups of modern civilized societies becomes a greater and greater problem. The regulative institutions of society, such as government, law, religion, and education, have to grapple with this problem of adjusting individuals to the requirements of an increasingly complex social life. No doubt religion, government, and law have a great function to perform in increasing social regulation, but they can only perform it effectively after they enlist education on their side.