Benjamin Franklin, in a letter to Joseph Priestley in 1772, who asked him for advice on decision making with "Prudent Algebra" > In the Affair of so much Importance to you, wherein you ask my Advice, I cannot for want of sufficient Premises, advise you what to determine, but if you please I will tell you how. > > When these 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 endeavour 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 tho’ 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 likely 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. Wishing sincerely that you may determine for the best, I am ever, my dear Friend, Yours most affectionately > B Franklin Another way to do this balance sheet is to rank the criteria specifically across dimensions rather than doing just pros and cons. | Criteria | Weight | Laptop A | Laptop B | Laptop C | | ------------ | ------ | -------- | -------- | -------- | | Performance | 0.5 | 8 | 7 | 9 | | Battery Life | 0.3 | 7 | 9 | 6 | | Price | 0.2 | 6 | 8 | 7 | | Total Score | | 7.3 | 7.8 | 7.5 | You can also "calibrate" the weights and scores iteratively: * Generate first version based on the scores and weight that make sense * Look at total score. * If it matches with your gut feeling, stop. * If it doesn't, look at the alternatives that are "out of order", and figure out whether you need to adjust an individual score, or weights of criteria * Repeat By the end of this process you'll have discovered your preferences in a clearer way. This is **not** necessarily the best way to make a decision because all this math is [[False Precision]]. This is why decisions made by [[Single Decisive Reason]] are more robust. #published 2025-01-26