As for concrete existents in the external world, they are grasped without any need for such syllogism.

The Universal Syllogism Is Built upon Analogy

If it is said that some people do come to know certain external particulars by means of this syllogism, then that syllogism in fact rests on analogical inference—the very method they deny can yield certainty. They are therefore faced with two alternatives: should they admit that analogical inference belongs to the same class as the universal syllogism and, like it, divides into demonstrative and probable forms, their distinction collapses. But if they claim that the two differ and that only the universal syllogism is certain while analogy is not, we reject the claim and show that certainty in such matters is obtained only through analogy. One learns what was previously unknown among the external particulars by comparing it with those particulars that are already known—an undeniable truth that no rational person contests.

Indeed, this is among the intellect’s most specific qualities, distinguishing it from the senses. The senses apprehend only the individual, whereas the intellect apprehends it as an unrestricted universal, yet only by way of analogy. After that, the intellect continues to comprehend every instance even when the concrete examples have faded from memory; originally, however, the concept became a general universal in the mind only after he had conceived definite examples of its instances. When the mind’s familiarity with those particulars grows distant, it often slips—either extending the judgment too broadly or restricting it too narrowly. This happens to people frequently.

Kinds of Imagined Constructs

From here arises much error among those who follow their path: they suppose the universal propositions they possess are sound, but careful examination proves otherwise. They conceive a thing in their minds; what they have conceived is intelligible to the intellect, whereupon they discuss it and imagine they are speaking about a pure quiddity in itself—independent of any existence, whether external or mental. Thus they say, “man insofar as he is man,” “existence insofar as it is existence,” “blackness insofar as it is blackness,” and so forth. They think that this quiddity, stripped of every positive or negative qualification, is realized externally in precisely that abstracted form. That is an error—the same mistake their predecessors made in their earlier abstractions.