material substance; but, in the case of the primary qualities, the extension is perceived, and, therefore, the idea resembles the quality, whereas when the extension becomes so small as to be imperceptible, it then gives rise to smells, tastes, and other nonresembling ideas. If this be Locke's meaning, we naturally ask, how is it that secondary qualities do not exist in bodies? If they are simply primary qualities divided into particles so small as not to offer resistance to pressure, there appears no reason for saying that they have no objective existence at all. This is another instance of Locke's confusion. We must now see how Locke's principles were treated by his successors in psychological research. SECTION IV. BERKELEY (1684–1753). CHAP. III. SECT. IV. clearness. § 55. When we compare the subtlety and clear- Berkeley's ness of the mental analysis found in the writings of Bishop Berkeley with the confusion perceptible in Locke, we might fancy that we had advanced at least a century onwards in the history of thought. In Berkeley we have the first English philosopher who obtained a clear insight into the problems of the psychology of perception. And his solution of some of these problems has not been improved upon to the present day, except, perhaps, in the manner of expression. We shall endeavour to give, as briefly as possible, an outline of the psychological doctrines of which he is the author. CHAP. III. SECT. IV. New theory of vision. Berkeley's Essay towards a New Theory of Vision was his first published philosophical work, and may serve us here as an introduction to his system. In it we have Berkeley's departure from the crude dualism of practical life and his theory of the manner in which that dualism is established. The following are the positions which he takes and defends : "(1.) Distance, or the fact of an interval between two points in the line of vision,-in other words, externality in space, in itself invisible,-is, in all cases in which we appear to see it, only suggested to our imagination by certain visible phenomena and visual sensations, which are its arbitrary signs. 66 ́(2.) Magnitude, or the external space that objects occupy, is absolutely invisible; all that we can see is merely a greater or less quantity of colour, and our apparently visual perceptions of real magnitude are interpretations of the tactual meaning of colours and other sensations in the visual organ. "(3.) The situation of objects, or their relation to one another in space, is invisible; all that we can see is variety in the relations of quantities of colour to one another, our supposed pure vision of actual locality being an interpretation of visual signs. "(4.) There is no sensible object common to sight and touch; space or extension, which has the best claim to this character, and which is nominally the object of both, is specifically as well as numerically different in each-externality in space, or distance, being absolutely invisible, while size and situation, as visible, have nothing in common with size and CHAP. III. situation as tangible. “(5.) The explanation of the unity which we attribute to sensible things, as complements of visible and tangible qualities of one and the same substance, is contained in the theory that visible ideas and visual sensations, arbitrary signs in a Divine Language, are significant of distances and of the real sizes and situations of distant things; while the constant association in nature of the two worlds of vision and touch has so associated them in our thoughts, that visible and tangible extension are habitually regarded by us as specifically, and even numerically, one. “(6.) The proper object of Geometry is the kind of Extension given in our tactual experience, and not the kind of Extension given in our visual experience, and neither real planes can be seen-real extension in all its phases being invisible, and colour in its modifications of quantity being the only proper object of sight, while colour, being a pure sensation, cannot exist extra-organically in space." "" * SECT. IV. of theory. § 56. The substance of the New Theory may be Substance thus expressed: The perception by sight of distance, magnitude, and direction, or of bodies as existing without us and being extended, is not an original but an acquired power. In sight we are conscious only of colour, but as this sensation and various tactual sensations are frequently experienced contemporaneously, we fancy the object of sight is * Prof. Fraser's analysis in his edition of Berkeley. CHAP. III. SECT. IV. Objects of identical with the object of touch. And since it is the tactual qualities of bodies in which we have the greatest practical interest, visible colour and extension soon, by association, become simply signs to call up the tactual qualities of bodies supposed to be more real. There are some points in connection with this theory which may offer matter for criticism hereafter, but, in the meantime, we shall take a further view of Berkeley's psychology by quoting from his Principles of Human Knowledge,' Part I. :— (1.) "It is evident to anyone who takes a survey of knowledge. the objects of human knowledge, that they are either ideas actually imprinted on the senses; or else such as are perceived by attending to the passions and operations of the mind; or, lastly, ideas formed by help of memory and imagination—either compounding, dividing, or barely representing those originally perceived in the aforesaid ways. By sight, I have the ideas of light and colours, with their several degrees and variations. By touch, I perceive hard and soft, heat and cold, motions and resistance, and of all these more or less either as to quantity or degree. Smelling furnishes one with odours, the palate with tastes; and hearing conveys sounds to the mind in all their variety of tone and composition. And as several of these are observed to accompany each other, they come to be marked by one name. Thus, for example, a certain colour, taste, smell, figure, and consistence having been observed to go together, are accounted one distinct thing, signified by the name apple. . . . CHAP. III. SECT. IV. mind. (2.) "But besides all that endless variety of ideas or objects of knowledge, there is likewise something which knows or perceives them, and exercises divers Knowing operations, as willing, imagining, remembering, about them. This perceiving, active being is what I call mind, spirit, soul, or myself. By which words I do not denote any one of my ideas, but a thing entirely distinct from them, wherein they exist, or, which is the same thing, whereby they are perceived-for the existence of an idea consists in its being perceived. have men tal exis (3.) "That neither our thoughts, nor passions, nor Objects ideas, formed by the imagination, exist without the mind, is what everybody will allow. And to me it tence only. is no less evident that the various sensations or ideas imprinted on the sense, however blended or combined together (that is, whatever objects they compose), cannot exist otherwise than in a mind perceiving them. I think an intuitive knowledge may be obtained of this by any one that shall attend to what is meant by the term exist when applied to sensible things. The table I write on, I say, exists, that is, I see and feel it; and if I were out of my study I should say it existed, meaning thereby that if I was in my study I might perceive it, or that some other spirit actually does perceive it. (7.) "From what has been said, it is evident there No matter. is not any other substance than spirit, or that which perceives. . . . For an idea to exist in an unperceiving thing is a manifest contradiction, for to have an idea is all one as to perceive; that, therefore, wherein colour, figure, &c., exist must perceive H |