The nature of the mind is to slip from one's grip. Concentration is the practice which enables the mind -- which, so to speak, strengthens its own fingers -- to hold fast whatever it can hold. Another secret of the mind is that even with the power of concentration the mind does not hold anything that is not interesting, and it is sympathy in the mind which is the stimulus to the holding power of the mind. Therefore no one can be a successful healer unless his sympathy comes forward with its hands extended to raise the patient from his pain.