Abstract
THE methodological principle known as Ockham’s Razor is usually formulated as “Entia non sunt multiplicanda praeter necessarium”. However, it is well known that neither this formulation of the principle nor the idea behind it come originally from William of Ockham. This particular formula is due to Leibniz, though Ockham’s works contain equivalent formulas: “Pluralitas non est ponenda sine necessitate”; “Si duae res sufficiunt ad eius veritatem, superfluum est ponere aliam rem”; “Frustra fit per plura, quod potest fieri per pauciora”. But Duns Scotus had also used the same principle before Ockham and he refers it directly to Aristotle. If the Razor belongs to anyone then, it belongs to Aristotle, and the study of its exact meaning and value must begin with Aristotle’s views about it. It is interesting to note, in this respect, that the principle was recognized as Aristotle’s at least until the time of Galileo. Thus in his Dialogue concerning the Two chief World Systems Galileo supports his theory that “diurnal motion belongs to the earth alone rather than to the rest of the universe excepting the earth” by referring to “a very true maxim of Aristotle’s which teaches that ‘frustra fit per plura quod potest fieri per pauciora’.”