Introduction to the Philosophy and Writings of Plato

...immortality of the soul from the hypothesis of separate forms.

Syrianus Syrianus (died c. 437 AD) was a Greek Neoplatonist philosopher and the teacher of Proclus; he was known for harmonizing the philosophies of Pythagoras, Plato, and Aristotle., in his commentary on the 13th book of Aristotle's Metaphysics, shows in defense of Socrates, Plato, the Parmenideans, and Pythagoreans, that ideas were not introduced by these divine men according to the usual meaning of names, as was the opinion of Chrysippus, Archedemus, and many of the junior Stoics The Stoics were a rival school of philosophy who argued that "Ideas" were merely mental constructs or "concepts" rather than independent realities.; for ideas are distinguished by many differences from things which are denominated from custom. Nor do they subsist, says he, together with intellect, in the same manner as those slender conceptions which are denominated universals abstracted from sensibles This refers to the idea that "universal" concepts (like "beauty") are just things we mentally "peel away" from physical objects, rather than being real things in themselves., according to the hypothesis of Longinus: for if that which subsists is unsubstantial, it cannot be consubsistent with intellect.

[11] See my translation of Aristotle's Metaphysics, p. 347. If the reader conjoins what is said concerning ideas in the notes on that work, with the introduction and notes to the Parmenides in this, he will be in possession of nearly all that is to be found in the writings of the ancients on this subject.

[12] It appears from this passage of Syrianus that Longinus Longinus (c. 213–273 AD) was a famous rhetorician and philosopher; here, the author credits him with a theory of "abstract ideas" that would much later be made famous by the English philosopher John Locke. was the original inventor of the theory of abstract ideas; and that Mr. Locke was merely the restorer of it.

Nor are ideas according to these men notions, as Cleanthes afterwards asserted them to be. Nor is idea definite reason, nor material form; for these subsist in composition and division, and verge to matter. But ideas are perfect, simple, immaterial, and impartible natures. And what wonder is there, says Syrianus, if we should separate things which are so much distant from each other? Since neither do we imitate in this particular Plutarch, Atticus, and Democritus, who, because universal reasons perpetually subsist in the essence of the soul, were of opinion that these reasons are ideas: for though they separate them from the universal in sensible natures, yet it is not proper to conjoin in one and the same the reason of soul, and an intellect such as ours, with paradigmatic and immaterial forms, and demiurgic intellections That is, the creative thoughts of the Divine Creator.. But as the divine Plato says, it is the province of our soul to collect things into one by a reasoning process, and to possess a reminiscence Reminiscence is the Platonic theory that "learning" is actually the soul "remembering" truths it knew before it was born. of those transcendent spectacles, which we once beheld when governing the universe in conjunction with divinity. Boethus, the peripatetic too, with whom it is proper to join Cornutus; thought that ideas are the same with universals in sensible natures. However, whether these universals are prior to particulars, they are not prior in such a manner as to be denudated Stripped or bared. from the habitude which they possess with respect to them, nor do they subsist as the causes of particulars; both which are the prerogatives of ideas; or whether they are posterior to particulars, as many are accustomed to call them, how can things of posterior origin, which have no essential subsistence, but are nothing more than slender conceptions, sustain the dignity of fabricative ideas?

[13] This was a Greek philosopher, who is often cited by Simplicius in his Commentary on the Predicaments, and must not therefore be confounded with Boethius, the Roman senator and philosopher.

In what manner then, says Syrianus, do ideas subsist according to the contemplative lovers of truth? We reply, intellectually and tetradically original: "noeros kai tetradikos"; "Tetradically" refers to the Pythagorean sacred number four, symbolizing order and completion., in the animal itself original: "en to antozoo"; This refers to the Autozoon, the "Intelligible Living Being" which contains the blueprints for all life., or the extremity of the intelligible order; but intellectually and decadically original: "noeros kai dekadikos"; "Decadically" refers to the number ten, representing the full manifestation of divine power., in the intellect of the artificer of the universe; for, according to the Pythagoric Hymn, “Divine number proceeds from the retreats of the undecaying monad, till it arrives at the divine tetrad which produced the mother of all things, the universal recipient, venerable, circularly investing all things with bound, immovable and unwearied, and which is denominated the sacred decad, both by the immortal gods and earth-born men.”

For the divine number proceeds, as the Pythagorean hymn to it says original: "Proeisi gar o Theios arithmos, os phesin o Pythagoreios eis auton umnos",
From the pure retreat of the Monad original: "Monados ek keuthmonos akeralou" until it reaches
The divine Tetrad, which brought forth the mother of all things original: "esti'an iketai Tetrada epi zatheen, he de teke metera panton",