I need not point out the advantages of modelling in a material as durable as stone. . . . Mixed up with just enough water to form a stiff paste, it accommodates itself to the touch of the modelling tool. . . . There are two inherent difficulties in using it—one, it is not so tractable as clay. . . .
At leaſt five Hundred of theſe reforming Vultures are daily plundering our Pockets, and ranſacking our Houſes, leaving me ſometimes not one pair of Tractable Buttocks in my Vaulting-School to provide for my Family, or earn me ſo much as a Pudding for my next Sundays Dinner :.
Some masters can be quite kind if you're meek and tractable.
This assumption is in the Raiffa and Schlaifer (1961, p. 72) spirit of using ‘a little ingenuity. . . to find a tractable function’ to quantify risk-preferences and probability judgments so as to make the analysis feasible.