Nominalism

What Nominalism means is a good question. One way to answer it, is to see what those who called themselves 'Nominalist' thought they were up to. The following is from a letter sent by some of the Masters of Paris University to King Louis XI in 1473. The translation is by James Walsh from pp. 322-3 of F. Ehrle, Der Sentenzen-kommentar Peters von Candia, Munster: Aschendorffsche Verlagsbuchhandlung, 1925. It is quoted in Hyman and Walsh, Philosophy in the Middle Ages, Indianapolis 1973 (a good book, if you can get a copy of it).

Those doctors are called Nominalists who do not multiply the things principally signified by terms in accordance with the multiplication of the terms. Realists, however, are those who contend on the contrary that things are multiplied according to the multiplicity of terms. For example, Nominalists say that divinity and wisdom are one and the same thing altogether, because everything which is in God, is God. But realists say that the divine wisdom is divided from divinity.

Again, those are called Nominalists who show diligence and zeal in understanding all the properties of terms on which the truth and falsity of a sentence depends, and without which the perfect judgment of the truth and falsity of propositions cannot be made. These properties are: supposition, appellation, ampliation, restriction, exponible distribution. They especially understand obligations and the nature of the insoluble, the true foundation of dialectical arguments and their failure. Being instructed in these things, they easily understand concerning any given argumentation whether it is good or bad. But the realists neglect these things, and they condemn them, saying, 'We proceed to things, we have no concern for terms.' Against them Master John Gerson said, 'While you proceed to things, neglecting terms, you fall into complete ignorance of things themselves.' This in his treatise on the Magnificat; and he added that the said Realists involve themselves in inexplicable difficulties, since they seek difficulty where there is none, unless it is logical difficulty.

The first point, that Nominalists do not multiply things according to the multiplicity of terms, is wholly Ockham. 'Radix est multiplicare entia secundum multitudinem terminorum, et quod quilibet terminus habet quid rei' - the root [of the error made by Realists] is to multiply entities according to the multiplicity of terms, and [to suppose] that to any term whatsoever there is a thing that corresponds. This is often confused with the idea that plurality is not to be posited without necessity. This does not originate with Ockham, and he never said this in any of his works that we know of. It was a common saying in the Middle Ages, believed by Nominalists and Realists alike. The issue is over what things count as necessary. The second point, that with the correct logical analysis, unnecessary entities will be seen to be unnecessary, is also Ockham.

We see many [people] who, neglecting this science [and nevertheless] wishing to devote themselves to learning, wander about all over the place scattering various errors around in [their] teaching, making up opinions full of absurdity with no restraint or order, weaving and putting together scarcely intelligible statements, suffering from something like the dreams of sluggards and the fictions of poets, ignorant of the meaning of their own speech. They are all the more dangerously in error the more they regard themselves as wise in comparison with others, recklessly hurling falsehoods indiscriminately in place of truths at the ears of their listeners. (from the introduction to the Summa Logicae, transl. Spade).