The secret of life is the desire to attain something; the absence of this makes life useless. Hope is the sustenance of life; hope comes from the desire of attaining something. Therefore this desire is in itself a very great power. The object which a person wishes to attain may be small compared with the power he develops in the process of attainment. The Hindus call attainment Sadhana; the power gained through attainment is called in Sanskrit Siddhi, and it is this which is the sign of spiritual mastership.