Every faculty has a tendency to act more and more quickly. Every activity starts from a rhythm that is productive, and when the activity is increased the rhythm becomes progressive, and if it is increased still more the rhythm becomes destructive. These three rhythms are called in Sanskrit Satva, Rajas, and Tamas. It is only by control that one can keep the productive and progressive nature; lack of control allows destruction to set in. The will alone has the power to control each activity, either of the body or of the mind. When a person walks he wishes to walk faster, when he speaks to speak more quickly. It is the nature of activity to tend to increase its speed, and if this increase is permitted, very soon the destructive element comes about. The stronger this faculty of control becomes in a person the stronger the person becomes, and the more one loses the power of control the weaker one becomes.