Note 26 — Chapter XXVIII · THEÆTETUS.

Bishop Berkeley observes:—

“But, say you, surely there is nothing easier than to imagine trees, for instance, in a park, or books existing in a closet, and nobody by to perceive them. I answer, you may so — there is no difficulty in it. But what is all this, more than framing in your mind certain ideas which you call books and trees, and at the same time omitting to frame the idea of any one that may perceive them? But do not you yourself perceive or think of them all the while? This therefore is nothing to the purpose. It only shows you have the power of imagining or forming ideas in your mind: but it doth not show that you can conceive it possible the objects of your thought may exist without the mind. To make out this, it is necessary that you conceive them existing unconceived or unthought of, which is a manifest repugnancy. When we do our utmost to conceive the existence of external bodies, we are all the while only contemplating our own ideas. But the mind, taking no notice of itself, is deluded to think it can and doth conceive bodies existing unthought of or without the mind, though at the same time they are apprehended by or exist in itself.”

Berkeley, Principles of Human Knowledge, sect. xxiii. p. 34, ed. of Berkeley’s Works, 1820. The same argument is enforced in Berkeley’s First Dialogue between Hylas and Philonous, pp. 145-146 of the same volume.

I subjoin a passage from the work of Professor Bain on Psychology, where this difficult subject is carefully analysed (The Senses and the Intellect, p. 370). “There is no possible knowledge of the world except in reference to our minds. Knowledge means a state of mind: the knowledge of material things is a mental thing. We are incapable of discussing the existence of an independent material world: the very act is a contradiction. We can speak only of a world presented to our own minds. By an illusion of language we fancy that we are capable of contemplating a world which does not enter into our own mental existence: but the attempt belies itself, for this contemplation is an effort of mind.”

“Solidity, extension, space — the foundation properties of the material world — mean, as has been said above, certain movements and energies of our own bodies, and exist in our minds in the shape of feelings of force, allied with visible and tactile, and other sensible impressions. The sense of the external is the consciousness of particular energies and activities of our own.”

(P. 376). “We seem to have no better way of assuring ourselves and all mankind, that with the conscious movement of opening the eyes there will always be a consciousness of light, than by saying that the light exists as an independent fact, without any eyes to see it. But if we consider the fact fairly we shall see that this assertion errs, not simply in being beyond any evidence that we can have, but also in being a self-contradiction. We are affirming that to have an existence out of our minds, which we cannot know but as in our minds. In words we assert independent existence, while in the very act of doing so we contradict ourselves. Even a possible world implies a possible mind to conceive it, just as much as an actual world implies an actual mind. The mistake of the common modes of expression on this matter is the mistake of supposing the abstractions of the mind to have a separate and independent existence. Instead of looking upon the doctrine of an external and independent world as a generalisation or abstraction grounded on our particular experiences, summing up the past and predicting the future, we have got into the way of maintaining the abstraction to be an independent reality, the foundation, or cause, or origin, of all these experiences.”

To the same purpose Mr. Mansel remarks in his Bampton Lectures on “The Limits of Religious Thought,” page 52:

“A second characteristic of Consciousness is, that it is only possible in the form of a relation. There must be a Subject or person conscious, and an Object or thing of which he is conscious. There can be no consciousness without the union of these two factors; and in that union each exists only as it is related to the other. The subject is a subject only in so far as it is conscious of an object: the object is an object only in so far as it is apprehended by a subject: and the destruction of either is the destruction of consciousness itself. It is thus manifest that a consciousness of the Absolute is equally self-contradictory with that of the Infinite.… Our whole notion of Existence is necessarily relative, for it is existence as conceived by us. But Existence, as we conceive it, is but a name for the several ways in which objects are presented to our consciousness — a general term embracing a variety of relations.… To assume Absolute Existence as an object of thought is thus to suppose a relation existing when the related terms exist no longer. An object of thought exists, as such, in and through its relation to a thinker; while the Absolute, as such, is independent of all relation.”

Dr. Henry More has also a passage asserting the essential correlation on which I am here insisting (Immortality of the Soul, ch. ii. p. 3). And Professor Ferrier, in his Institutes of Metaphysic, has given much valuable elucidation respecting the essential relativity of cognition.

Though this note is already long, I shall venture to add from an eminent German critic — Trendelenburg — a passage which goes to the same point.

“Das Sein ist als die absolute Position erklärt worden. Der Begriff des Seins drücke blos das aus: es werde bei dem einfachen Setzen eines Was sein Bewenden haben. Es hat sich hier die abstracte Vorstellung des Seins nur in eine verwandte Anschauung umgekleidet; denn das Gesetzte steht in dem Raum da; und insofern fordert die absolute Position schon den Begriff des seiendem Etwas, das gesetzt wird. Fragt man weiter, so ist in der absoluten Position schon derjenige mitgedacht, der da setzt. Das Sein wird also nicht unabhängig aus sich selbst bestimmt, sondern zur Erklärung ein Verhältniss zu der Thätigkeit des Gedankens herbeigezogen.

“Aehnlich würde jede von vorn herein versuchte Bestimmung des Denkens ausfallen. Man würde es nur durch einen Bezug zu den Dingen erläutern können, welche in dem Denken Grund und Mass finden. Wir begeben uns daher jeder Erklärung, und setzen eine Vorstellung des Denkens und Seins voraus, in der Hoffnung dass beide mit jedem Schritt der Untersuchung sich in sich selbst bestimmen werden.” “Indem wir Denken und Sein unterscheiden, fragen wir, wie ist es möglich, dass sich im Erkennen Denken und Sein vereinigt? Diese Vereinigung sprechen wir vorläufig als eine Thatsache aus, die das Theoretische wie das Praktische beherrscht.” Trendelenburg, Logische Untersuchungen, sect. 3, pp. 103-104, Berlin, 1840.