Says Sri Krishna in the Bhagavad Gita (2.67): "If the mind yields to even one of the wandering senses, it carries away one's discrimination, even as a gale carries away a ship on the waters." It may take us a while to realize that we began to do something but then were dragged away elsewhere by the mind. This condition is inevitable as long as we identify ourselves with the mind and are forced to do its bidding. We begin to feel the need to discipline the mind only when we accept our miserable state of slavery to it. Concentration is impossible as long as the mind remains undisciplined. The mind begins to act as our friend only when we bring it more and more under control.
The Mahabharata (Shanti Parva, 250.4) defines true austerity: "Concentration of the mind and senses is the highest tapas [austerity]. Since it is higher than all other virtues, it is called the highest virtue." This highest austerity is entirely different from concentration of mind on objects of enjoyment. Tapas involves weaning the mind from its usual pursuits and focusing it on something that is beneficial to us. Buddhi comes into play in mind control when we assert our will, exercise the power of discrimination between right and wrong, and think, perceive, and act accordingly. When we do not exercise the buddhi, our mental impressions and external circumstances control our thoughts, perceptions and actions.
The Katha Upanishad (1.3.3-9) compares buddhi to the charioteer of a chariot. The chariot can reach its destination only if the charioteer is wide awake and the horses (senses) are controlled. Similarly, the goal of human life-the Supreme Abode of God-can be reached only when the sensory system and the mind are disciplined by an awakened buddhi.
Concentration of mind on external tasks is a lesser challenge, but essential for success in everyday life. Spiritual life, however, calls for a different type of concentration. To achieve this concentration, we need to exercise the will, detach the mind from senses and objects, and fix it on a divine name and a divine form within. And that is true austerity.
The Bhagavad Gita (17.14-16) classifies austerity into three kinds.
"Worship of the gods, of the twice-born, of teachers, and of the wise; cleanliness, uprightness, continence, and non-violence-these are said to be austerity of the body." (17.14)
"Words that do not give offense and that are truthful, pleasant, and beneficial, and also the regular recitation of the Vedas-these are said to be austerity of speech." (17.15) A well-known Sanskrit verse explains how to be truthful in speech: "Speak what is truthful, speak what is pleasant, but do not speak an unpleasant truth. Nor should you speak an untruth just because it is pleasant to hear. This is the way of eternal religion."
"Serenity of mind, gentleness, silence, self-control, and purity of heart-these constitute austerity of the mind." (17.16) According to Sri Ramanuja, serenity of mind refers to absence of anger, gentleness means being helpful to others, and silence means control of speech by the mind. A forced silence unaccompanied by mind control is not of much help.