It was during this interval that Mr. Rittenhouse experienced a long course of exemption from any very conspicuous public employments, which could interfere with his favourite studies; an interval, in which he was disposed to have enjoyed a kind of dignified leisure, amidst the tranquillity of domestic employments; so far as the existing state of things in the political world would permit a man, solicitous for his country’s happiness, to participate in any sort of gratification, that might be deemed incompatible with a due degree of interest in the public weal. He possessed too enlightened and patriotic a mind not to be keenly sensible of the delicate, as well as alarming situation, in which his country was then placed. But nature had fitted him for the quiet station of domestic life, and the delightful pursuits of natural science; rather than for the bustle of official situation, and for those speculative projects in politics, wherein specious theories often terminate in the most deceptive results. He had been investigating principles founded in Truth, from his childhood; this object was always near to his heart; and he set little value on any thing that did not lead to its attainment. This predominating disposition of his mind is indeed plainly evinced by a single sentence, contained in a letter which he addressed to Mr. Barton, so early as the 16th of February, 1764. Having had a personal interview with an eminent and worthy clerical gentleman, well disposed to befriend him, but who was more a metaphysical than a natural philosopher, he thus expressed himself on the occasion: “I had a good deal of conversation with Mr. ******, not, perhaps, greatly to the satisfaction of either of us; for he appears to me to be a Mystical Philosopher, and you know I care not a farthing for any thing but sober Certainty in Philosophy.”