Berkeley seeks, in metaphysics, direct spiritual intuition; in physics, to abolish what would prevent this intuition. The mystics from whom Berkeley had learned so much had built their system of philosophy upon such an intuition, and made it their one thing needful. But their spiritual intuition was an intuition which was said to be enjoyed in meditations and trances, not in life and work. The world of things seen and handled did not bring them into direct communion with spirit; it was rather a veil to cloud the vision, a clog to hinder the endeavour of the human spirit ever trying to get beyond it. The senses and sense-knowledge were despised, and only behind the veil which it hung athwart the soul was there that universe of things unseen and eternal which More and Norris delighted to expatiate upon; or, if the senses did in any dim and uncertain way reveal the invisible spiritual realities longed for, it was because the soul, rising above them, put a divine meaning into them, and revelled in the 'lusciousness of this inward sense.' Such a hazy, unreal way of conceiving the spirit-life which he believed to be the true reality, was distasteful to Berkeley. He wished to keep to the spiritual intuition, which was the one good thing in these mystical doctrines, but he wished to bring it out of dreamland, and make it serviceable for every-day work and endeavour. Both More and Norris dreamt of an Atlantis, and celebrated its praises in prose and verse; Berkeley set sail for America to create the Utopia he had visioned. More and Norris could only realise the spiritual intuition on which they based their philosophy in an ecstatic contemplation, when the soul is borne on the wings of meditation far beyond this world of sensible things; Berkeley employs his spiritual intuition to account for puzzles in vision, errors in mathematics, and the virtues of tar-water. He wishes to mould and fashion, to give clearness and distinctness of outline to the spiritual beliefs and intuitions of the mystics by applying to them the method of Locke and Bacon. He wishes to conserve and give value to the fundamental truths which lie unshaped in the scholastic Realism, by applying to them the clearness and methods of Nominalism. This is, we believe, the key to Berkeley's life and philosophy.
Let us try to show its application.
The English mystics were the reaction against a phase of the new philosophy which had been so developed by Hobbes as to create a strong counter opinion. This phase was the doctrine of an inert matter which is so prominent in the writings of Descartes and Geulinx—matter, whose distinguishing characteristic was extension, which was entirely void of all power to act or to influence, and which was set up in opposition to spirit, whose distinguishing characteristic or property was consciousness. This theory of matter was so void of all real meaning that the existence and properties of material substance became gradually of less importance in a system of philosophy, and at length, as in Malebranche and Norris, ceased to have any influence on their speculations. It was outside their system, and of little or no account in its explanation. Yet the very semblance of its presence prevented a thorough-going attempt to explain the real meaning of reality, power, and causality, and recourse is had to meditation and ecstasy instead of to philosophical explanation and analysis. Locke's philosophy, on the other hand, with its calm, experimental analysis of the facts of knowledge, and its concentration of effort upon the senses and the knowledge they supplied, had brought the mind of man back to facts, and pointed to another path than that of vision or ecstasy, by which one might ascend to the understanding of what is meant by the world of things known and knowable. But if Locke is always judicious, he is never deep. He solved the theory of substance more by ignoring than by explaining it; and his Atomism, if one may call it so—his assertion that all knowledge is of particulars, and particulars only—not only turned him aside from any complete statement of causality, but forced him into theories of abstract ideas or conceptions that seem inconsistent with his own principles. When Locke had to account for the fact that this, that, and the other, sensation of colour were felt to be the same, he explains away this seeming contradiction to his favourite doctrine that all knowledge is of particulars, by saying that there is an abstract idea of whiteness framed from the particular ideas or sensations. But the necessities of language, thought, and science require that this abstract idea of whiteness must be as often, if not oftener, before the mind than any one of the particular ideas out of which it has been constructed, and thus the abstract idea is much more important than the particular sensation. When Locke is called on to give an account of our knowledge and its origin, his Atomism is always brought forward; when he wishes to speak of truth, certainty, &c., he cannot help paying more attention to abstract ideas. He thus figures two worlds just as the mystics had done, the sensible and intelligible, and while elevating the worth of the former, is inclined to make certainty, demonstration, &c., belong to the latter.
Locke's theory of abstract ideas was an hypothesis to account for and explain a really objective knowledge—that is, a knowledge which is true for others as well as for the individual. Objectivity, in this simple sense of the word, was a great difficulty in Locke's system. He had reduced all our ideas to ideas of sense and of reflection. He had insisted on the purely subjective origin of whatever is known. And at the same time he had insisted that what was known in this way were particular things and particulars only. He seems both in his account of the origin of knowledge, and in his description of the things known, to exclude the possibility of a knowledge common to several individuals at once. Each man seems rather to be shut within the sphere of his own ideas of sense and reflection about certain particular objects. But a subjective theory of knowledge and things known cannot be maintained. It would render all social intercourse impossible. There could be neither language, propositions, nor even common nouns. And the theory of abstract ideas is the way out of the difficulty. Now Berkeley, with his strong spiritual intuition, regarded Locke's system of abstract ideas very much as Aristotle, with his strong faith in progressive motion towards a final end (τελος), looked at Plato's ideal theory. It was only reproduction, a shadowy reflection, a cold crystallization of the world of sense ideas, and really did nothing to explain the life, motion, and order of the sense-world, nor furnished us with a basis for our real common or objective knowledge. We do not think that Berkeley altogether appreciated Locke, nor fully recognised the use which he, as well as Hobbes, had made of the doctrine of association of ideas, to explain community of knowledge and objective certainty. For in Hobbes and Locke we see the beginnings of that modern psychological theory which, under the names of association of ideas and relativity of knowledge, explain the existence, permanence, and objectivity of things and classes of things by a manifold flow of phenomena. Ideas or sensations, by rubbing themselves against consciousness, in various ways coalesce into things, and things into those possibilities of reproduction, intercourse, and communion which are represented by common nouns. But Berkeley had been taught by the mystics to associate motion, cause, and sensation with spirit or mind, and he could not see that Locke's doctrine of association, so void of conscious life or personal activity, might at least prove so nearly allied to his own doctrine of causality that it might be called its external wrapping. And even if Berkeley had seen this, we may excuse him from acknowledging what he owed to Locke in this matter, and forcing into prominence, in opposition to Locke's teaching, his intuition of direct spiritual agency, when we find how the association theory has not freed us from the abstractions which Berkeley dreaded, but still gives us such shadowy conceptions as the 'unconditioned' of Hamilton, or the 'unknown cause' of Mill. Berkeley admired Locke, and studied him carefully. His great aim was to keep Locke's results, to retain Locke's philosophy, but to give it new life. His philosophy was to be Lockianism stript of its notionalism, and inspired in all its parts by that direct spiritual intuition which was never absent from his mind. It was to be Locke's philosophy, with these differences: the starting-point of the system was to be the human self—the conscious ego—the type of all subsistence: and an association theory producing a second world of abstract ideas was to be supplanted by the continuous active causality of personal spirits; or, more shortly, it was to be Locke's philosophy, with living personal causality put instead of abstract ideas.[224]
If we take this as the fundamental thought in Berkeley's speculation we find three stages of development in his philosophy. In his 'Common-place Book,' and in the 'Principles,' he fancies, in his youthful fervour, that he has only to strip Locke's philosophy of its notionalism and the true system of metaphysics will appear. Hence his speculation in this first period is mainly negative. It is a war against abstractions, and his positive theories are more hinted at than explained. The second period is revealed in his philosophical letters to Dr. Samuel Johnson. He begins to find that there is more to be done in philosophy than to extirpate abstract ideas, and inquires into the archetypes of things. The third period is given us in 'Siris.' His philosophy has got deeper and perhaps less dogmatic. He was won to the grand thought of an organic universe of things, in which their whole is made for all the parts, and every part for the whole, and for the other parts; so that the virtues of tar-water are intimately connected by a multiform concatenation with the constant presence and continual agency of the God in whom we live and move and have our being. The first period in Berkeley's speculation is, as we have said, mainly negative. It is a polemic against abstract ideas in their various forms. The attack is earnest, eager, but also impatient and inadequate. We have only hints at construction. It seems as if he thought he had only to deny false modes of explanation in order to state the right one, and his discussion throughout bears the stamp of eagerness and impetuosity. It represents the man who could say of those who doubted the success of his American enterprise, 'that small-minded persons had a talent for objections.' This period is represented in the 'New Theory of Vision,' 'The Principles of Human Knowledge,' and 'The Dialogues between Hylas and Philonous.' Its negative character may be due to accident. These three works are confessedly an imperfect sketch of Berkeley's principles. The 'Theory of Vision' is a mere tentative introduction; the 'Principles,' as we have them, are only the first part of a work which, if we are to trust 'The Common-place Book,' was meant to include three parts, and was published as Part I. The 'Dialogues' are only the 'reproduction of the first part of the 'Principles of Human Knowledge.' They are all of them imperfect expositions of Berkeley's speculative opinion. Taking them as they are, however, let us endeavour to discover the fundamental thoughts in each.
It has been for some time acknowledged that the essay towards A New Theory of Vision is not to be summed up in the dictum that distance is invisible. The invisibility of distance is the psychological basis of the theory.[225] The work is rather the first blow in the attack upon Locke's 'Doctrine of Abstract Ideas':—
'The treatise is, in short, a professed account count of the facts, the whole facts, and nothing but the facts, of which we are visually conscious, as distinguished from pretended facts and metaphysical abstractions, which confused thought, an irregular exercise of imagination, or an abuse of words had substituted for them.'
The question which Berkeley really asks is—How do we universalize our ideas of sight? The proper objects of sight are light and colours. How, then, do we see distance, figure, size, situation, magnitude and solidity? How can the sensation of green colour peculiar to my mind stand for, not the mere sense-blur of vague green colour, but an oval leaf fluttering in the wind some twenty feet above me, attached to the twig of a beech tree! and, moreover, how can this sensation which belongs to me so far belong to others that the same knowledge conveyed to me is also given to them? How can the vague subjective sensation be universalized so that it stands for several things not felt, and more especially for sensations of touch? What is the link between these various qualities? What is the bridge by which the mind passes over from the one to the other? This link is not, says Berkeley, an abstract idea of extension, in which the visible and tangible sensations unite, for there is no such idea. The sensations of sight and of touch are on their side quite heterogeneous:—
'The extension, figures, and motions perceived by sight are specifically distinct from the ideas of touch, called by the same names; nor is there any such thing as one idea, or kind of idea, common to both senses.'