Robert Grosseteste (1168–1253 AD) in his treatise On Truth elaborates on the concept of exemplarism and truth, and states that:

• Platonic forms, as eternal models or examples, exist in God’s mind.
• Things (and not just propositions) have truth-value.
• The Aristotelian conception of truth as conformity/adequation of the speech to the things is modified by Grosseteste, by considering the speech to be that of God, the eternal Word. In this sense, each thing can have two truth-values: (1) “the eternal reason of a thing specifies the very kind of thing that thing is” – which is always true, and (2) if the thing fulfills its ethernal function – which can be true or false.
• In this way, we can epeak or more truths, but at the end “for Grosseteste any use of the term ‘truth’ involves in some way a reference to the supreme truth, God.”

The following OntoUML diagram presents Robert Grosseteste’s model of truth:

Class	Description	Relations
God’s(Mind)	“Grosseteste’s exemplarism […] is in part an adaptation of Plato’s theory of Ideas to a Christian framework. Like other medieval thinkers, Grosseteste takes the existence of an eternal, self-subsistent realm of Platonic Ideas to be inconsistent with the dependence of all things on God. Nevertheless, following Augustine and Seneca, he does not reject the Platonic ideas outright. Rather, he treats them as eternal models (exempla) or, as he also calls them, reasons (rationes) of things in God’s mind.“	creates Thing
EternalWord	“Grosseteste claims that the eternal Word is itself its very own conformity to itself and thus may be identified with truth.	exclusive part of God’s(Mind); describes EternalModel
EternalModel	“Grosseteste’s exemplarism […] is in part an adaptation of Plato’s theory of Ideas to a Christian framework. Like other medieval thinkers, Grosseteste takes the existence of an eternal, self-subsistent realm of Platonic Ideas to be inconsistent with the dependence of all things on God. Nevertheless, following Augustine and Seneca, he does not reject the Platonic ideas outright. Rather, he treats them as eternal models (exempla) or, as he also calls them, reasons (rationes) of things in God’s mind. Like the Platonic ideas, these reasons function as paradigms or models created things can accord with or fall short of. God looks to these reasons of things in creation, somewhat as a craftsman looks to the idea in his mind of what he is to make. Given that God is absolutely simple, the reasons of things in God’s mind must in the final analysis be identified with God. Thus Grosseteste moves between speaking of the reasons in God’s mind as exemplars or models and speaking of God himself as such.”	exclusive part of God’s(Mind); model for Thing
Truth	“truth (veritas) is a conformity between things and the eternal Word. […] As for created things, their truth is their conformity to their eternal model or reason in the eternal Word.[…] the truth of propositions—a subclass of things—is their conformity to their eternal model or reason in the eternal Word. “ Each Thing (and Proposition) can have one or, two truths: ● (1) “On the one hand, the eternal reason of a thing specifies the very kind of thing that thing is, and simply in virtue of existing as an item of a determinate kind a thing will necessarily conform to its exemplar in this respect and be true. Thus all human beings and all propositions are true, in this sense, in that they are the kinds of things they are, this being specified by their exemplar. A human being is a composite of body and soul, and a proposition is ‘the statement of one thing about another or one thing from another’ […] ● (2) “On the other hand, the eternal reason specifies the second perfection a thing ought to have but may nonetheless lack. In this sense a human being will be a false human being if, for example, she is vicious, falling short of the perfection of virtue specified in the eternal reason of a human being. Likewise, a proposition will be a false proposition if it fails to perform the function of a proposition, this being to state things as they in fact are in the world. Thus, the ordinary notion of propositional truth, described by Aristotle as ‘to so be in the thing signified as speech says,’ is a matter of a proposition’s conformity, in respect of second being, to its eternal reason, and this is for it to perform the function perfective of propositions, namely, to be in conformity to the states of affairs it asserts.”	mediates between EternalWorld and Thing
Conformity	Conformity or adequation	characterizes Truth
Thing	Thing
Proposition	Proposition is a sentence with tuth-value.	subkind of Thing

Sources

• All citations from: Lewis, Neil, “Robert Grosseteste”, The Stanford Encyclopedia of Philosophy (Summer 2019 Edition), Edward N. Zalta (ed.)

First published: 03/09/2020