of mind marked by him as most apt to interfere with the formation
of beliefs in harmony with the Universal Reason that is active in the
universe.
IV. Philosophy.—The Essay Concerning Human Understanding embodies Locke’s philosophy. It was the first attempt on a great scale, and in the Baconian spirit, to estimate critically the certainty and the adequacy of human knowledge, when confronted with God and the universe.
The “Introduction” to the Essay is the keynote to the whole. The ill-fortune of men in their past endeavours to comprehend themselves and their environment is attributed in a great measure to their disposition to extend their inquiries into matters beyond the reach of human understanding. To inquire with critical care into “the original, certainty and extent of human knowledge, together with the grounds and degrees of belief, opinion and assent,” is accordingly Locke’s design in this Essay. Excluding from his enquiry “the physical consideration of the mind,” he sought to make a faithful report, based on an introspective study of consciousness, as to how far a human understanding of the universe can reach. Although his report might show that our knowledge at its highest must be far short of a “universal or perfect comprehension of whatsoever is,” it might still be “sufficient” for us, because “suited to our individual state.” The “light of reason,” the “candle of the Lord,” that is set up in us may be found to shine bright enough for all our purposes. If human understanding cannot fully solve the infinite problem of the universe, man may at least see that at no stage of his finite experience is he necessarily the sport of chance, and that he can practically secure his own wellbeing.
The last book of the Essay, which treats of Knowledge and Probability, is concerned more directly than the three preceding ones with Locke’s professed design. It has been suggested that Locke may have begun with this book. It contains few references to the foregoing parts of the Essay, and it might have appeared separately without being much less intelligible than it is. The other books, concerned chiefly with ideas and words, are more abstract, and may have opened gradually on his mind as he studied more closely the subject treated in the fourth book. For Locke saw that the ultimate questions about our knowledge and its extent presuppose questions about ideas. Without ideas knowledge is impossible. “Idea” is thus a leading term in the Essay. It is used in a way peculiar to himself—“the term which, I think, stands best for whatsoever is the object of the understanding when a man thinks” or “whatever it is which the mind can be employed about.” But ideas themselves are, he reminds us, “neither true nor false, being nothing but bare appearances,” phenomena as we might call them. Truth and falsehood belong only to assertions or denials concerning ideas, that is, to our interpretations of our ideas according to their mutual relations.
That none of our ideas are “innate” is the argument contained in the first book. This means that the human mind, before any ideas are present to it, is a tabula rasa: it needs the quickening of ideas to become intellectually alive. The inward purpose of this famous argument is apt to be overlooked. Innate ideas. It has been criticized as if it was a speculative controversy between empiricism and intellectualism. For this Locke himself is partly to blame. It is not easy to determine the antagonist he had in view. Lord Herbert is referred to as a defender of innateness. Locke was perhaps too little read in the literature of philosophy to do full justice to those more subtle thinkers who, from Plato downwards, have recognized the need for categories of the understanding and presuppositions of reason in the constitution of knowledge. “Innate,” Lord Shaftesbury says, “is a word Mr Locke poorly plays on.” For the real question is not about the time when ideas entered the mind, but “whether the constitution of man be such that, being adult and grown up, the ideas of order and administration of a God will not infallibly and necessarily spring up in him.” This Locke himself sometimes seems to allow. “That there are certain propositions,” we find him saying, “which, though the soul from the beginning, or when a man is born, does not know, yet, by assistance from the outward senses, and the help of some previous cultivation, it may afterwards come certainly to know the truth of, is no more than what I have affirmed in my first book” (“Epistle to Reader,” in second edition). And much of our knowledge, as he shows in the fourth book, is rational insight, immediate or else demonstrable, and thus intellectually necessary in its constitution.
What Locke really objects to is, that any of our supposed knowledge should claim immunity from free criticism. He argues in the first book against the innateness of our knowledge of God and of morality; yet in the fourth book he finds that the existence of God is demonstrable, being supported by causal necessity, without which there can be no knowledge; and he also maintains that morality is as demonstrable as pure mathematics. The positions are not inconsistent. The demonstrable rational necessity, instead of being innate, or conscious from our birth, may lie latent or subconscious in the individual mind; but for all that, when we gradually become more awake intellectually, such truths are seen to “carry their own evidence along with them.” Even in the first book he appeals to the common reason, which he calls “common sense.” “He would be thought void of common sense who asked, on the one side, or, on the other, went to give a reason, why ‘it is impossible for the same thing to be and not to be.’ It carries its own light and evidence with it, and needs no other proof: he that understands the terms assents to it for its own sake, or else nothing else will ever be able to prevail with him to do it” (bk. i. chap. 3, § 4).
The truth is that neither Locke, on the one hand, nor the intellectualists of the 17th century, on the other, expressed their meaning with enough of precision; if they had, Locke’s argument would probably have taken a form less open to the charge of mere empiricism. Locke believed that in attacking “innate principles” he was pleading for universal reasonableness instead of blind reliance on authority, and was thus, as he says, not “pulling up the foundations of knowledge,” but “laying those foundations surer.” When men heard that there were propositions that could not be doubted, it was a short and easy way to assume that what are only arbitrary prejudices are “innate” certainties, and therefore must be accepted unconditionally. This “eased the lazy from the pains of search, stopped the inquiry of the doubtful, concerning all that was once styled innate. It was no small advantage to those who affected to be masters and teachers to make this the principle of principles—that principles must not be questioned.” The assumption that they were “innate” was enough “to take men off the use of their own reason and judgment, and to put them upon believing and taking upon trust without further examination. . . . Nor is it a small power it gives one man over another to have the authority to make a man swallow that for an innate principle which may serve his purpose who teacheth them” (bk. i. chap. 4, § 24).
The second book proposes a hypothesis regarding the genesis of our ideas and closes after an elaborate endeavour to verify it. The hypothesis is, that all human ideas, even the most complex and abstract and sublime, ultimately depend upon “experience.” Otherwise, what we take to be ideas are Genesis of ideas. only empty words. Here the important point is what human “experience” involves. Locke says that our “ideas” all come, either from the five senses or from reflective consciousness; and he proposes to show that even those concerned with the Infinite depend at last on one or other of these two sources: our “complex ideas” are all made up of “simple ideas,” either from without or from within. The “verification” of this hypothesis, offered in the thirteenth and following chapters of the second book, goes to show in detail that even those ideas which are “most abstruse,” how remote soever they may seem from original data of outward sense, or of inner consciousness, “are only such as the understanding frames to itself by repeating and joining together simple ideas that it had at first, either from perceiving objects of sense, or from reflection upon its own operations.”
To prove this, our thoughts of space, time, infinity, power, substance, personal identity, causality, and others which “seem most remote from the supposed original” are examined in a “plain historical method,” and shown to depend either on (a) perception of things external, through the five senses, or on (b) reflection upon operations of the mind within. Reflection, “though it be not sense, as having nothing to do with external objects,” is yet, he says, “very like it, and might properly enough be called internal sense.” But the suggestion that “sense” might designate both the springs of experience is misleading, when we find in the sequel how much Locke tacitly credits “reflection” with. The ambiguity of his language makes opposite interpretations of this cardinal part of the Essay possible; the best we can do is to compare one part with another, and in doubtful cases to give him the benefit of the doubt.
Although the second book is a sort of inventory of our ideas, as distinguished from the certainty and boundaries of our knowledge, Locke even here makes the assumption that the “simple ideas” of the five senses are practically qualities of things which exist without us, and that the mental “operations” discovered by “reflection” are those of a person continuously existing. He thus relieves himself of the difficulty of having at the outset to explain how the immediate data of outward sense and reflection are accepted as “qualities” of things and persons. He takes this as a fact.
Such, according to Locke, are the only simple ideas which can appear even in the sublimest human speculations. But the mind, in becoming gradually stored with its “simple ideas” is able to elaborate them in numberless modes and relations; although 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 the other of these two ways. All that man can imagine about the universe or about God is necessarily confined to them. For proof of this Locke would have any one try to fancy a taste which had never affected his palate, or to frame the idea of a scent he had never felt, or an operation of mind, divine or human, foreign to all human consciousness.
The contrast and correlation of these two data of experience is
suggested in the chapter on the “qualities of matter” in which we
are introduced to a noteworthy vein of speculation
(bk. ii. chap. 8). This chapter, on “things and their
qualities,” looks like an interpolation in an analysis of
Qualities
of matter.
mere “ideas.” Locke here treats simple ideas of the five senses
as qualities of outward things. And the sense data are, he
finds, partly (a) revelations of external things themselves in their
mathematical relations, and partly (b) sensations, boundless in
variety, which are somehow awakened in us through contact and
collision with things relatively to their mathematical relations.
Locke calls the former sort “primary, original or essential qualities
