 One deduction involves the comparison of scientific investigation to the use of the rule of the false position in arithmetic: “Here a first position is obtained, which, though not accurate, approaches, however, to the truth. From this, applied to the equations, a second position is deduced, which approaches nearer to the truth than the first; from the second a third, etc.” Hartley adds that “this is indeed the way, in which advances in science are carried on; and scientific persons are aware, that it is and must be so” (OM 1, prop. 87).