Sri Aurobindo
Letters of Sri Aurobindo
Volume II - Part 1
It is a universally accepted principle of the spiritual endeavour that one must be prepared to sacrifice everything without reserve in order to reach the Divine through a spiritualised consciousness. If self-development on the mental, vital and physical plane is his aim that is another matter – that life is the life of the ego with the soul kept behind undeveloped or half developed. 
But for the spiritual seeker the only development he seeks is the development of the psychic and spiritual consciousness and that too, only because it is necessary to reach and to serve the Divine, not for its own sake. Whatever mental, vital, physical development or use of faculties can be made part of the spiritual life and an instrumentation for the Divine can be kept on condition of surrender of them for transformation and restatement on the spiritual basis. But they must not be kept for their own sake or for the sake of the ego or considered as one’s own possession or used for one’s own purpose but only for the sake of the Divine.
As for James’ statement1 it is of course true except in so far as the politician can indulge in other things as hobbies for his leisure hours, but if he wants to succeed as a politician he must give his best energies to politics. Conversely if Shakespeare or Newton had spent part of their energies in politics they would not have been able to reach such heights in poetry and in science or even if they had they would have done much less. The main energies have to be concentrated on one thing; the others can only be minor pursuits at leisure or for distraction or interests rather than pursuits useful for keeping up a general culture.