Stedman and Hutchinson, comps. A Library of American Literature: An Anthology in Eleven Volumes. 1891. Vol. III: Literature of the Revolutionary Period, 17651787
To Joseph Priestley, With a Method of Deciding Doubtful Matters
By Benjamin Franklin (17061790)
IN the affair of so much importance to you, wherein you ask my advice, I cannot, for want of sufficient premises, counsel you what to determine; but, if you please, I will tell you how. When those difficult cases occur, they are difficult, chiefly because, while we have them under consideration, all the reasons pro and con are not present to the mind at the same time; but sometimes one set present themselves, and at other times another, the first being out of sight. Hence the various purposes or inclinations that alternately prevail, and the uncertainty that perplexes us.
To get over this, my way is, to divide half a sheet of paper by a line into two columns; writing over the one pro and over the other con; then during three or four days consideration, I put down under the different heads short hints of the different motives, that at different times occur to me for or against the measure. When I have thus got them all together in one view, I endeavor to estimate their respective weights; and, where I find two (one on each side), that seem equal, I strike them both out. If I find a reason pro equal to some two reasons con, I strike out the three. If I judge some two reasons con, equal to some three reasons pro, I strike out the five; and thus proceeding I find at length where the balance lies; and if, after a day or two of farther consideration, nothing new that is of importance occurs on either side, I come to a determination accordingly. And, though the weight of reasons cannot be taken with the precision of algebraic quantities, yet, when each is thus considered separately and comparatively, and the whole lies before me, I think I can judge better, and am less liable to make a rash step; and in fact I have found great advantage from this kind of equation, in what may be called moral or prudential algebra .