LOCKE 759 things and persons. In order to make his theory work, he begins by assuming a hypothetical duality beneath phenomena, some phenomena referable to external things, others referable to the conscious self, and in fact confesses that this dual experience is the ultimate fact, the denial of which would make it impossible to speak about the growth and constitution of our thoughts. In the early chapters of the second book, the " simple " thoughts into which he promises to resolve all possible "complex " ones are arranged in classes. Some of them, he reports, are conditioned " by one sense only," as colours by sight, or heat, cold, and solidity by touch; others " by more senses than one," as space or extension and motion, which are perceivable both by the eyes and by touch ; a third class are got from reflexion only, when " the mind turns its view inward upon itself," and by this means we get our ideas of perception or thinking itself, and also of willing, as well as the " modes of these two," such as remembrance, discerning, reason ing, knowledge, faith, &c. ; lastly, there are simple ideas which we have both from sensation and reflexion, for instance, our thoughts of bodily and mental pleasures and pains, as well as thoughts of existence, unity, power, and succession. Such, according to Locke, are the elements of the sublimest human thoughts. While the mind is becoming gradually stored with simple ideas bike these (which are, however, somehow complex for us, when we " are conscious of them "), we find a growing power to elaborate them for ourselves at pleasure in an almost infinite variety ; we are in fact obliged to do this in our tentative endeavours inductively to bring the thoughts of our individual minds into harmony with the actual complexity of thought that is presented to us in the order of nature. " But it is not in the power of the most exalted wit or enlarged understanding to invent or frame any new simple idea not taken in in one or other of these two ways," in proof of which Locke would have any one try to fancy any taste which had never affected his palate, or to frame the thought of a scent he had never smelt ; and when he can do this he is ready to concede that a born blind man has ideas of colours, and a born deaf man notions of sounds. The contrast and correlation of these two fountains of indi vidual experience is suggested in the eighth chapter of this book, on the "qualities" of matter, in which we are introduced to a noteworthy vein of speculation running through the Essay. A chapter on " qualities of things" looks like an interpolation in an examination of our individual thoughts ; its relevancy appears when we remember Locke s provisional hypothesis, according to which simple ideas of sense may also be viewed as qualities of things. Now, our original sense-thoughts are, we find, partly revelations of external things themselves in their essential externality or extension, and partly sensations, boundless in their variety, which are some how raised in us through contact with the things. Locke calls the former primary, original, or essential qualities of matter, and the others its secondary or derived qualities. The primary, which in volve mathematical relations, and might be called quantities rather than qualities, are inseparable from matter as matter, and somehow exactly correspond, he reports, to the thoughts we have of them. On the other hand, there is nothing in the mathematical relations of space-occupying body which in the least resembles our ideas or thoughts of the secondary qualities ; they are qualities of bodies at all, rather than sensations in us, only in so far as our different secondary sensations somehow correlate with (unknown) sizes, shapes, and motions of the primary particles, with which they are thus in an established harmony. Therefore, if there were no sentient and intelligent beings in existence, the secondary qualities would cease to exist, except perhaps as unknown modes of the pri mary, or, if not, as " something still more obscure." On the other hand, " solidity, extension, figure, motion, and rest would be really in the world as they are, whether there were any sensible being to perceive them or not" (bk. ii. chap. 21, 2). The outcome of what Locke teaches about the mutual relations of matter (a) known as occupied-space, and (b) known in and through the sensations caused by secondary or relative qualities, is that it is something capable of being expressed at once in terms of mathematical quan tity or extension, and also in terms of sense-consciousness. A further step would have led to the conception of the correlative dependence of all the so-called qualities of bodies upon "the bulk, figures, number, situation, and motions of the solid parts of which they consist," and which "exist as we think of them whether or not they are perceived." The true conception of an individual body would then be a conception of the actual mathematical relations of the atoms of which it consists, regarded as the established "occasions" of the sensations of colour, resistance, sound, taste, or smell which we refer to it as qualities ; and also of the changes that it occasions in the atoms of which other individual bodies consist, which are followed by their operating on sentient beings differently from what they did before, as when the sun melts wax. But Locke only suggests in a hesitating way that the powers of bodies which are manifested in sensible changes may be conditioned by unknown changes in the mathematical relations of their insen sible atoms, or, if not thus dependent upon them, conditioned by " something yet more remote from our comprehension." For, not knowing what size, figure, and texture of parts they are on which depend and from which result those qualities which make our complex idea, for example, of gold, "it is impossible v:e should know what other qualities result from, or are incompatible with, the same constitution of the insensible parts of gold, and so consequently must always coexist with that complex idea we have of it, or else are inconsistent with it. " Some of the most remarkable chapters in the second book are those which relate to the verification of its initial proposition. They carry us towards the metaphysical mysteries which so attract meditative minds. The hypothesis that our most complex thoughts are all resolvable into "experience" is tested in these chapters by the modes or modifications, and substantiations, and relations which, in various degrees of complexity, we find ourselves somehow obliged to make the simple phenomenal thoughts of sense and reflexion undergo. Such, for instance, are the thoughts of finite quantity in space and time and number, in which Locke reports that we find ourselves mentally impelled towards immensity, eternity, and the innumerable, that is to say, towards Infinity, which transcends quantity ; the complex thought of Substance, towards which he reports that we find ourselves impelled in another of the "opera tions of our minds," when the simple phenomena of the senses have to be regarded as powers or qualities of something " ; the thought of the Identity of individuals, involved in the apparently inconsistent idea of their constant phenomenal changes ; and, above all, the mental tendency we find we somehow have to suppose what we call a "Cause " whenever we observe a change. Let us see how Locke deals with these crucial instances. He dwells much on our ideas of Space, Succession, and Number. The first he says begins to appear when we use our senses of sight and touch ; the second he finds suggested " by all the phenomena of sense, but still more by " what passes in our minds" ; the third is "suggested by every object of our senses, and every thought of our minds, by everything that either doth exist or can be imagined." The modifications of which these three sorts of simple ideas are susceptible he reports to be "inexhaustible and truly infinite, extension alone affording a boundless field to the mathematicians." In his own patient judicial way, he finds many curious analogies between space and time. Neither is limited by the world of indivi dual things. We can imagine space without bodies, but we cannot perceive or imagine bodies without space. Places and periods are all relative to objects and events, but both space and time are absolutely indivisible. A trinal space extends in all directions, while time has only one dimension. All things exist in the same present time, while no two things occupy the same space. The parts of time cannot be thought to coexist ; the parts of space cannot be thought to succeed one another. Whether the thought of unoccu pied space is the thought of a substance or of an attribute Locke professes that he cannot tell, at least till they that ask show him "a clear distinct idea of substance." But the real mystery which he has to report of these thoughts of space and time is that "some thing in the mind" hinders us from imagining any limit to either. We find ourselves, when we try, obliged to lose our positive thought of space in the negative thought or Immensity, and our positive thought of time in the negative thought of Eternity. We have never seen, and we cannot mentally imagine, an object whose extent is boundless. Yet we find when we reflect that there is an "operation of the mind which somehow forces us to think that space and time have no limits. "I would fain meet with that thinking man that can in his thoughts set any bounds to space more than he can to duration" ( 21). Thus Locke by implication acknowledges something added by the mind to the originally pre sented " simple ideas " of extension and succession, though he explains that what is added is not positively imaginable. When we reflect on our thoughts of immensity and eternity, we find them to be thoughts, yet negations of all imaginable thought ; and that whether we proceed by addition or by division. He characteristi cally accepts the fact ; he does not inquire v:hy mind should find itself thus obliged to add without limit, and to divide without limit. He simply reports that immensity and eternity arc inevitable negative ideas, and that every endeavour to transform them into positive or imaginable ones only issues in the contradictory attempt to represent as a bounded quantity what is really infinite or beyond quantity. The idea of the infinite, or unquantifiable in extent and in succession, has so far, he finds, "something that is resolvable into the simple positive ideas of space and time." For, when we try to think of the infinite in space or duration, we at first usually make some very large idea (imaginable in itself, though by men unimaginable), as perhaps of millions of miles or ages, which possibly we multiply millions of millions of times. All that we thus amass in our thoughts is positive (i.e., imaginable in its nature, although not imaginable by a human mind). But at the end of this we are as far from the infinite reality as we were at the beginning, so that what lies beyond the imaginable idea towards the infinite lies "in obscurity, and lias the indeterminate confusion of a negative idea " irresistible and incomprehensible.
