"Every person of learning is finally his own teacher; the reason of which is, that principles, being of a distinct quality to circumstances, cannot be impressed upon the memory; their place of mental residence is the understanding, and they are never so lasting as when they begin by conception."
The Age of Reason; Being an Investigation of True and Fabulous Theology. 
Thomas Paine, <u>The Age of Reason; Being an Investigation of True and Fabulous Theology. </u> (Paris: Printed by Barrois, London: Sold by D. I. Eaton, 1794). &lt;<a href="http://oll.libertyfund.org/title/1083">Link to Liberty Fund's Online Library of Liberty</a>&gt;