“The depth and intensity of the friendship will depend upon variety and extent of the things we do and enjoy together. Will the friendship be constant? That again depends upon the permanence of our common interests, and upon whether or not our interests grow into ever-widening circles, so that we do not stagnate. The highest friendship demands growth. “It must be progressive as life itself is progressive.” Friends must walk together; they cannot long stand still together, for that means death to friendship and to life.”