Diagram of Ens Reale

Ens Reale (Greek: φύσις [physis]; mind-independent being):

Esse (To exist):

-In

--Alio (another): Accident

--Se (itself): Substance

-Ad (towards/for): Relation

Hence although relation is grouped within the accidents because it isn't substance, relation is unlike any accident insofar as it does not exist intrasubjectively but suprasubjectively, dependent upon subjectivities as its foundation yet above them. Accidents properly speaking are intrasubjective determinations that specify the substance as an individual.

Ockham's reduction of relation to similarity existing between subjectivities that possess intrasubjectively a same quality or determination (accident) is a reduction of relation as suprasubjective to intra- and inter- subjective. Relation therefore loses its proper characteristic and becomes an expression of the multiplication of some similar quality or being; if two or more beings share this quality, there is relation in the shared quality.

Relation, interestingly, is characterized precisely by its indifference to the orders of ens reale and ens rationis, mind-independent and mind-dependent being. A relation may exist even if its fundament or terminus exist either in ens reale or ens rationis; hence whether the relation is a "real relation" or just a "logical" one. For example, a relation of fictions is still a relation even though fictions are related; hence even though the fundament and terminus are within ens rationis, the relation is real (not as in "real relation" but simply as existing). But an individual that is a fiction is precisely not an individual because an individual is that which exists independently of ens rationis. Relation bridges the gap and is therefore also the bridge between culture and nature.

Relation is also the bridge between subjectivity (individuality of substances, ens reale) and objectivity (ens reale that has become an ens rationis through the awareness of a cognitive or quasi-cognitive power). Something becomes an object precisely by coming into relation with a subject that possesses some power of awareness.

Cf. John Deely, Purely Objective Reality (2009), ch. 2.