Note 44 — Chapter XXVIII · THEÆTETUS.

The terms Ego and Mecum, to express the antithesis of these two λόγῳ μόνον χωριστὰ, are used by Professor Ferrier in his very acute treatise, the Institutes of Metaphysic, pp. 93-96. The same antithesis is otherwise expressed by various modern writers in the terms Ego and non-Ego — le moi et le non-moi. I cannot think that this last is the proper way of expressing it. You do not want to negative the Ego, but to declare its essential implication with a variable correlate; to point out the bilateral character of the act of consciousness. The two are not merely Relata secundum dici but Relata secundum esse, to use a distinction recognised in the scholastic logic.

The implication of Subject and Object is expressed in a peculiar manner (though still clearly) by Aristotle in the treatise De Animâ, iii. 8, 1, 431, b. 21. ἡ ψυχὴ τὰ ὄντα πώς ἐστι πάντα· ἢ γὰρ αἰσθητὰ τὰ ὄντα ἢ νοητά. ἐστὶ δ’ ἡ ἐπιστήμη μὲν τὰ ἐπιστητά πως, ἡ δ’ αἴσθησις τὰ αἰσθητά. The adverb πως (τρόπον τινά, as Simplikius explains it, fol. 78, b. 1) here deserves attention. “The soul is all existing things in a certain way (or looked at under a certain aspect). All things are either Percepta or Cogitata: now Cognition is in a certain sense the Cognita — Perception is the Percepta.” He goes on to say that the Percipient Mind is the Form of Percepta, while the matter of Percepta is without: but that the Cogitant Mind is identical with Cogitata, for they have no matter (iii. 4, 12, p. 430, a. 3, with the commentary of Simplikius p. 78, b. 17, f. 19, a. 12). This is in other words the Protagorean doctrine — That the mind is the measure of all existences; and that this is even more true about νοητὰ than about αἰσθητά. That doctrine is completely independent of the theory, that ἐπιστήμη is αἴσθησις.

It is in conformity with this affirmation of Aristotle (partially approved even by Cudworth — see Mosheim’s Transl. of Intell. Syst. Vol. II. ch. viii. pp. 27-28) — ἡ ψυχὴ τὰ ὄντα πώς ἐστι πάντα — that Mr. John Stuart Mill makes the following striking remark about the number of ultimate Laws of Nature:—

“It is useful to remark, that the ultimate Laws of Nature cannot possibly be less numerous than the distinguishable sensations or other feelings of our nature: those, I mean, which are distinguishable from one another in quality, and not merely in quantity or degree. For example, since there is a phenomenon sui generis called colour, which our consciousness testifies to be not a particular degree of some other phenomenon, as heat, or odour, or motion, but intrinsically unlike all others, it follows that there are ultimate laws of colour …The ideal limit therefore of the explanation of natural phenomena would be to show that each distinguishable variety of our sensations or other states of consciousness has only one sort of cause.” (System of Logic, Book iii. ch. 14, s. 2.)