The utmost thrift and industry of thinking give no man any stock in life; his credit with the inner world is no better, his capital no larger.
 Henry David Thoreau, A Week on the Concord and Merrimack Rivers (1849). copy citation

Context

“The life of a wise man is most of all extemporaneous, for he lives out of an eternity which includes all time. The cunning mind travels further back than Zoroaster each instant, and comes quite down to the present with its revelation. The utmost thrift and industry of thinking give no man any stock in life; his credit with the inner world is no better, his capital no larger. He must try his fortune again to-day as yesterday. All questions rely on the present for their solution. Time measures nothing but itself. The word that is written may be postponed, but not that on the lip.” source