  As with many other Platonists, Proclus’ epistemology is based on a theory of innate knowledge (in accordance with the Platonic dictum that ‘all learning is recollection [anamnêsis]’). Proclus refers to the innate contents of the soul as its reason-principles (logoi) or Forms (eidê). These innate reason-principles constitute the essence of soul. That is why they are called ‘essential reason-principles’ (logoi ousiôdeis) (Steel 1997). The traditional translation reason-principles was chosen on purpose, because on an ontological level these same logoi serve as principles of all things. They are extended or unfolded images of the Forms that exist in intellect; and by means of them the world-soul with the assistance of Nature brings forth everything. In other words, the psychic logoi are instantiations of Platonic Forms on the level of soul as are the logoi in Nature and the forms immanent in matter. According to the fundamental Neoplatonic axiom panta en pasin (‘all things are in all things’), Forms exist on all levels of reality. But the logoi in soul also offer the principles of all knowledge and are the starting points of demonstration. At In Parm. IV 894.3–18 (ed. Steel) Proclus argues that only with reference to these notions within the soul predication is possible (see Helmig 2008), since they are universal in the true sense of the word. On the other hand, both transcendent Platonic Forms and forms in matter are not taken to be universals proper by Proclus. The former are rather intelligible particulars, as it were, and cannot be defined (Steel 2004), while the latter are strictly speaking instantiated or individualised universals that are not shared by many particulars (see Helmig 2008, cf. above 3.1–2). For this reason, it does not make much sense to talk about ‘the problem of universals’ in Proclus.