the breakdown of scholasticism, as a precursor of Descartes or Kant or whoever might be the
particular commentator's favourite among modern philosophers. According to Moody, with
whom I agree, all this is a mistake. Occam, he holds, was mainly concerned to restore a pure
Aristotle, freed from both Augustinian and Arabic influences. This had also been, to a
considerable extent, the aim of Saint Thomas; but the Franciscans, as we have seen, had
continued to follow Saint Augustine much more closely than he did. The interpretation of
Occam by modern historians, according to Moody, has been vitiated by the desire to find a
gradual transition from scholastic to modern philosophy; this has caused people to read modern
doctrines into him, when in fact he is only interpreting Aristotle.
Occam is best known for a maxim which is not to be found in his works, but has acquired the
name of "Occam's razor." This maxim says: "Entities are not to be multiplied without
necessity." Although he did not say this, he said something which has much the same effect,
namely: "It is vain to do with more what can be done with fewer." That is to say, if everything
in some science can be interpreted without assuming this or that hypothetical entity, there is no
ground for assuming it. I have myself found this a most fruitful principle in logical analysis.
In logic, though apparently not in metaphysics, Occam was a nominalist; the nominalists of the
fifteenth century * looked upon him as the founder of their school. He thought that Aristotle had
been misinterpreted by the Scotists, and that this misinterpretation was due partly to the
influence of Augustine, partly to Avicenna, but partly to an earlier cause, Porphyry's treatise on
Aristotle Categories. Porphyry in this treatise raised three questions: (1) Are genera and species
substances? (2) Are they corporeal or incorporeal? (3) If the latter, are they in sensible things or
separated from them? He raised these questions as relevant to Aristotle's Categories, and thus
led the Middle Ages to interpret the Organon too metaphysically. Aquinas had attempted to
undo this error, but it had been reintroduced by Duns Scotus. The result had been that logic and
theory of knowledge had become dependent on metaphysics and theology. Occam set to work
to separate them again.
* E.g., Swineshead, Heytesbury, Gerson, and d'Ailly.