Locke's Theory of knowledge and its historical relations

Preface

THIS study of Locke's Theory of Knowledge was begun as an introduction to an edition of the Essay upon which I have been engaged for some years, but in view of the proportions to which it has grown it has seemed better that it should appear independently. Notwithstanding the labours of Campbell Fraser and the admirable little volume by Professor Alexander, the Essay still suffers from the twin assumptions, that it can be understood without being studied and that its full significance can be summed up in a small number of simple propositions. In truth, few philosophical classics lend themselves less readily to such summary treatment than do its carefully guarded statements, and its complex, unstable thought positions. In the exposition of Locke's doctrine, which occupies the first half of this book, I have, | accordingly, sought to indicate the grounds of my inter- ( pretation by frequent references and quotations. The relation of Locke's thought to that of his predecessors and contemporaries has hitherto received but little consideration, and that little not from his countrymen. To throw some further light upon the influences which affected his work has, consequently, been one of my chief aims. On { the other hand, I have omitted all reference to the movement which culminated in Hume, to have dealt with which I with the necessary fullness would too greatly have extended J the length of the present work. Concerning it I can only

VI

Preface remark that the exclusive attention bestowed upon it, as the story of the self-refutation of certain of Locke's principles, has been largely responsible for the false perspective in which the Essay itself is too commonly viewed. That the tendency to sensationalistic atomism was bound to work itself out is, indeed, true enough. But the significant fact that the course of the individual thought of Locke, of Berkeley, and even of Hume himself, favoured the fuller recognition of the intellectual functions involved in knowing and of the systematic character of what is known, suggests that there were other directions in which the doctrine of the Essay was susceptible of at least equally legitimate development.

Bangor.

Chapter I The Problem Of Knowledge And The 'new Way Of Ideas'

i. The main problem of the Essay is to determine the nature and possible

extent of human knowledge ....... (3/

g2. The characteristics of the knowledge it investigates f2

3. While the typical examples of this knowledge are found in the mathe-

matical sciences, its most important contents are the objects of

our moral and religious consciousness ..... 4

4. Of the problem thus propounded Locke thought he had found a

solution 7

J 5. The originality of his position 9

6. His division of the sciences and its bearing on the scope and pre-

suppositions of his enquiry n

7. Ideas: current applications of the term and Locke's usage . . 13

8. The 'formal' and 'objective' reality of ideas . . . . 15

9. The importance of the distinction and its dangers . . . 16

10. Locke's attitude to the distinction 18

11. The subordinate place of Psychology in the Essay , . . 21

12. The consequences which Locke drew from the nature of ideas as

explicit contents of thought 22

(a) They cannot be 'stored' in the memory ... 23

(b) They cannot be confused 24

(c) They are incapable of change and their relations are

eternal 25

13. Locke's later reflections on the metaphysical nature of ideas and

their relation to the mind .26

Vlll

Chapter II The Polemic Against Innate Principles

1. The appeal to 'Nature' in the seventeenth century: its vagueness

and confusion . 29

2. The question of innate principles not one of logical priority or of

mental activity 31

3. Its bearing upon Locke's theory of knowledge .... 33

4. The rival theory of certainty 34

5. The motives of Locke's polemic 36

6. His arguments 37

7. The polemic primarily directed against 'scholastic men' . . 39

8. Its wider reference 42

Chapter III The Origin And Formation Of Ideas

1. The consideration of ideas a preparation for that of knowledge . 45

2. The significance of the enquiry into the origin of ideas. The Com-

position theory and its influence 46

3. The nature of 'simple' ideas . . . . ... . . 50

4. Their origin in experience . 52

5. Simple ideas of Sensation and the conditions of their reception . 54

6. 'Reflection' and its conditions ....... 55

7. In what sense the mind is passive in the reception of simple ideas 57

8. The part played by mental activity in the actual process of experience 59

9. Their passive reception a guarantee of the 'reality' of simple ideas 61

10. In what sense complex ideas are 'the work of the mind' . . 61

11. A unifying function of the mind involved in all complex ideas . 62

12. 'Compounding,' 'comparing,' and 'abstracting' .... 63

13. Ideas of relations 66

14. General ideas * . . . . 67

Chapter IV The Contents Of Our Ideas Of Modes

1. Locke's objective classification of complex ideas .... 71

2. His account of simple modes implies that the simple idea is a

universal . . 72

3. Our ideas of number ......... 73

4. Space and its modes . . . . . . • • • 74

Contents ix

5. Duration and its modes 78

6. Our ideas of 'pure' space and 'pure' duration. . . . . 82

7. Our idea of infinity 83

8. Our ideas of non-quantitative simple modes and of mixed modes . 87

CHAPTER V iy OUR IDEAS OF SUBSTANCE, CAUSALITY AND IDENTITY

1. Special features of these ideas 91

2. Analysis of our ideas of substances ...... 92

3. Substance a supposition based on a necessity of thought . . 92

4. The part played by custom in the formation of our ideas of particular

substances and their kinds 93

5. The real nature of the inconsistency involved in Locke's position 94

6. We can form no positive idea of substance, which must, however, have

a character of its own . . . . . . . . <f$

7. The substance of mind and matter equally unknowable . . 97

8. Our ideas of matter . 99

9. Its primary and secondary qualities 100

10. Comparison between our ideas of matter and mind . . . 103

11. Our ideas of power and cause how related 105

12. They both imply active efficiency, a clear idea of which can only be

obtained from our experience in willing . . . . .106

13. The justification of the application of these ideas to unwilled changes 108

14. Causation and uniformity ........ 109

15. The idea of identity and its origin . . . . . .111

16. Identity of substance and other forms of identity . . . 111

17. Identity of self determined by 'continued consciousness' . . 114

18. It involves the presence of the higher intellectual powers . . 115

19. Identity of self and identity of person 116

20. Metaphysical significance of Locke's theory of identity of self . 118

Chapter VI The General Nature Of Knowledge

1. Subject of the chapter 1 20

2. The distinction between knowledge and opinion .... izi*S

3. Intuition and demonstration 124

4. The objectivity and necessity of knowledge . . . .126

5. The 'reality' of knowledge 128,.-

6. The reality of simple ideas . . . . . . . .130

X

SECT.

PAGE

7. The reality of ideas of modes and relations . « . . .131

*~'ie reality of ideas of substances 1^2

The instructive or synthetic character of real knowledge . . 135

The nature and grounds of opinion \yj

Error I4o

Chapter VII The Kinds And Limits Of Knowledge

h Initial four-fold classification of knowledge

vl2. First, of identity and diversity. This a presupposition rather than a kind of knowledge ......... 143

J 3. Significant affirmation is 'in concrete' and relational . . .143 ^4. Secondly, of relations between abstract ideas .... 145

-5. Examples of such knowledge . . . . . . . .147

6. The demonstrative character of mathematics .... 148

7. Upon what it depends 150

8. Influence of mathematics upon Locke's general conception of know-

9. Locke's view of the subject matter of Ethics .... 155

10. The demonstrability of Ethics . . . . . ... 157

11. Thirdly, of coexistence 160

12. Why it is so narrow . . . . . . . . .162

13. Fourthly, of real existence 166

14. No direct passage from idea to real existence. The ontological

argument . . . .168

15. Existence of Self known by intuition 169

16. 'Sensitive' knowledge of the existence of material things . . 172

17. Locke's final two-fold classification of knowledge . . . .176

18. His suggestions of a possible higher form of knowledge . . 179 xi

Chapter VIII Locke And Scholasticism

1. The difficulty of determining the sources of the doctrine of the .Essay 182

2. The principal influences which affected Locke's thought . * 183

3. Locke's view of Aristotle 185

4. The theory of knowledge attributed by Locke to the Schoolmen . 186-

5. 'Maxims' not the 'foundations' of our knowledge . . .187

6. The syllogism not the 'only proper instrument' of knowledge . 188

7. Locke's relation to the scholastic metaphysical scheme . . 189

8. The conception of substance 190

9. The unreality of relations 193

10. The doctrine of essence . . . . . . . . .196

1 1. Locke's criticism of the theory of substantial forms and of its supposed

bearing on classification * 199

13. The idea of God 204

Chapter IX Locke And Descartes

1. Locke's own account of his relation to Descartes .... 205

2. Importance of the Cartesian influence as regards

(a) The nature of rational knowledge; .... 206

(b) The conception of self-consciousness .... 207

3. The different spirits in which they approach the question of know-

4. (A) The nature of rational knowledge. Similarities of view . 211

5. Locke's modification of the Cartesian view ..... 212

6. His rejection of conceivability as a test of truth . . . .214

7. His insistence upon synthetiqfal judgments 21 5

8. His recognition of a second or empirical type of knowledge . . 215

9. His dissent from the Cartesian logic illustrated by his criticism, (a) of

the ontological argument • • « . . . . .216 xii Contents

10. (b) of the doctrine that thought is the essence of mind . . 217

11. (c) of the doctrine that extension is the essence of matter . . 219

12. (B) The Cartesian conception of self-consciousness: its influence

seen in Locke's theory of our knowledge of self, and in his acceptance of the representative theory of perception .... 222

13. The point of view of the Essay reached by a transformation of the

Cartesian conception ......... 223

14. The new point of view fatal to the dogmatic dualism of Descartes . 224

15. Influence of the different views of the principle of self-consciousness

held by Locke and Descartes upon their psychology . . . 226

16. Descartes' theory of innate ideas. Its two forms . . . 228

17. The bearing of Locke's polemic against innate principles upon

Descartes' position . . . 230

18. Connection of the theory of innate ideas with defects in the Cartesian

logic 23 1

Chapter X Locke And Contemporary English Philosophy

1. No positive influence from Bacon or Hobbes . . . .233

2. Locke and the Cambridge Platonists 236

3. Similarity of their views as to the nature and content of rational

knowledge 238

4. Locke and Cumberland 241

5. The nature of space. Views of Hobbes, More, and Newton . . 245

6. Locke's earlier views on this question 248

7. The view of the Essay: its indebtedness to Newton and More . 250

8. The nature of matter 254

9. The possibility of a science of nature: Locke and Glanville . . 258

10. Locke and Boyle 260

11. Conclusion 265

Chapter XI Locke And Leibniz

1. Relation of the Nouveaux Essais to the Essay .... 267

2. Leibniz's early reflections on the Essay 268

3. His ideal of rational knowledge . . . ... . 269

4. Clearness, distinctness and adequacy of ideas . . . .271 xm

5. Truths of reason and truths of fact 273

6 Connection of Leibniz's logic with his metaphysics . . . 275

7. The monadology and knowledge . 2j6x ^

8. His metaphysics necessitates an extended conception of mental

function 276

9. Locke's psychological difficulties from his adherence to the Cartesian

conception of mental function . 277

10. Leibniz's use of the conception of sub-consciousness . . . 278

11. His defence of innate principles and ideas 280

12. Are all ideas innate? . . .281

13. Leibniz's attempts to distinguish a special class of innate ideas or

principles

(a) Clear and distinct ideas innate 281

(b) Ideas involved in knowledge of self innate . . .282

(c) Universal and necessary truths innate .... 283

(d) Fundamental principles innate . . . . . 283

14. Locke's simple ideas of Sensation declared to be complex . . 286 f

15. Leibniz's general view of Locke's procedure in Book II . . 288''

16. His difficulties in connection with our spacial ideas . . . 289

17. His treatment of the idea of substance compared with that of Locke 291/

18. His view of relations 292 ,

CHAPTER XII LOCKE AND LEIBNIZ (continued)

1. The nature of knowledge: extent of agreement between Locke and

Leibniz 294 P*'

2. For Leibniz the primary truths of reason are identical propositions 295

3. His rejection of Locke's knowledge of relations .... 296 \ ^

4. His view of arithmetic and geometry 297

5. Demonstration in other subjects 298

6. Locke's conception of knowledge declared to be too stringent . 300

7. Leibniz's attempt to represent the varieties of knowledge as con-

tinuous 301

8. His two kinds of truths compared with Locke's two kinds of instructive

propositions 302

9. His attempt to mediate between truths of reason and truths of fact 303

10. His view of the relation between the mathematical and natural

sciences 305

11. Value of Leibniz's criticism of the Essay 307^

XIV

Chapter XIII Locke And Kant

A. Locke and Kant both aim at an immanent criticism of knowledge,

but are inconsistent . . . . . . . . .310

2. Similarity in their general conceptions of the problem and in the

resulting difficulties 312

3. Exemplified by their views of the reality of mind . . . .314

4. Locke's anticipation of the distinctions involved in the question,

'how are synthetic a priori judgments possible?' . . .316

5. A comparison of their treatment of non-rational knowledge . . 318

6. The reference to experience in their general theories of knowledge. 320

7. Locke's theory of universal and instructive propositions . . 321

8. His defective view of the nature of the universal and its relation to

9. How far qualified by him . . . . . . . .323

10. How his original position needs to be corrected .... 325

11. Kant's conception of transcendental logic 326

12. His failure to unite the universal and the particular factors of

experience 327!

13. A comparison of Locke and Kant in this respect .... 327

14. Their treatment of the categories compared 328

15. Conclusion 334

Index 335

Chapter I The Problem Of Knowledge And The 'new Way Of Ideas'

§ I. In the popular tradition as to the contents of the Essay concerning Human Understanding, which for so long satisfied even the most conscientious of our historians of Philosophy, its main purport was found in a theory of the genesis of ideas which, denying to the mind both activity and the possession of any definite character of its own, derived all the contents of our knowledge from particular data of immediate experience. In virtue of this theory its author was proclaimed the founder of modern Empiricism, and if any features of his work inconsistent with the role thus assigned to him received any notice at all, they were treated as unintentional departures from his fundamental position. The account which Locke gives of the origin of ideas, and his view of the nature of mind and its relation to experience, will occupy us later on, when it will be found that a good many mythical elements have become embedded in the popular tradition as to his views on these subjects. For the present we are only concerned to point out that any account of Locke's work which finds its main? significance in an account of the genesis of our ideas fails entirely to represent either the aim or the outcome of the Essay, as these were conceived by its author. Great as was the importance which he attached to his theory upon this subject, it played only a subordinate part in the scheme of

G. I the Essay as he designed it ; and any attempt to make it central alters entirely the perspective of the whole. While he considers that it contributes towards, he fully recognises that it does not contain in itself a solution of the problem which the Essay sets out to solve, viz., that of determining the nature and possible extent of human knowledge. Any exposition of the thought of Locke, as expressed in the Essay, must therefore begin by considering what he understood by knowledge, the nature and bounds of which he sought to ascertain.

§ 2. Philosophers of an empirical tendency have generally simplified the problem of their epistemology by reducing the claims of knowledge to the level of the principles by which they have sought to explain it. Unconditional validity, strict universality and necessity, cannot, they have maintained, belong to our judgments, which are merely the cumulative result of a number of particular experiences. The appearance of rational demon- ' stration is for them only a garb which is assumed by a form of cognition which rests at bottom upon particular data of immediate experience, and in so far as it transcends these is infected with uncertainty and imperfection. Such, however, is very far from being the position of Locke, For him, in the first place, knowledge and certainty are equivalent terms. 'With me,' he says, 'to know and to be certain is the same thing : what I know, that I am certain of; and what I am certain of, that I know. What reaches to knowledge, I think may be called certainty; \ and what comes short of certainty, I think cannot be called I knowledge1.' And this certainty which constitutes knowledge is an objective certainty, which must be distinguished from the highest degree of subjective assurance with

1 Second Letter to Stillingfleet, Works, vol. iv. p. 145.

and the c New Way of Ideas ' 3

which a merely probable conviction may be held. In some cases, he holds, the grounds of probability are so strong that our assent is as necessarily determined \ by them as by a strict demonstration, but even in these l extreme cases he still rigidly refuses the name of knowledge1. For when we have knowledge, we have something which excludes the possibility not only of doubt but of error. Now this does not merely mean that knowledge is formally distinguished from error, as the true from the false. It implies that ajorm of absolutely certain cognition exists^ which no new facts or considerations can ^ weaken or overthrow, and which is capable of being J recognised as such by the subject. ' WhaTwe once know, we are certain is so; and we may be secure that there are no latent proofs undiscovered, which may overthrow our knowledge or bring it in doubt2.'

Besides its certainty, there are two other general features which Locke considers that knowledge must possess, if it is to be of any serious value. In the first place, it must possess the character of being 'instructive' orjynthetic,"Ey which it is distinguished from the merely verbal certainty of the 6 trifling' propositions, which only repeat in the predicate the whole or a part of the idea which constitutes the subject. And further, however subjectively conditioned and limited in its immediate range, the knowledge which Locke undertakes to investigate is regarded by him as somehow referring to and holding gooaol a reality which is inde^endent"oTtEe knowing mind andoFTfrlTTHe^^ Besides being

c^rt^fn-arrd instructive, our knowledge must be 'real.'

Nor must it be supposed that this real and instructive certainty is to be found either exclusively or typically 1 iv. 17. 16. 8 iv. 16. 3.

in reference to particular matters of fact, of which our sense-perceptions might be supposed to render us cognisant. Such knowledge as this is distinguished by him as 'experimental' and 'historical' from the 'scientific' knowledge which consists of universal truths ; and it is with the latter that he is primarily concerned. The nature and extent of our knowledge of particular sensible facts would not, in the first instance, have presented itself to him as a problem requiring serious investigation, although in the end it proved a subject for curious consideration. For, upon

i reflection, it appeared that this 'historical' or 'experimental' knowledge is not only inferior in its limitation to the particular, but is also deficient in the quality of absolute certainty wruch constitutes the essence of knowle3ge. TJ^knw Locke is~chiefly con-

l "terned is, therefore, thatjwhkh consists in certain and universal propositions. Moreover, he holds that strictly universal statements can never be justified by a process j of empirical generalisation. On the contrary, the universal proposition is one which asserts a connection which is

^seenTo hold good trom the consideration_of the nature of the case^ It is, indeed, only universal in its range because this connection of content is seen to be necessary. It thus possesses all the characteristics of knowledge which is logically a priori. Upon such universal and necessary propositions, Locke considers, the possibility of demonstration depends, without which our knowledge would be entirely without system, and could not assume the form of science.

§ 3. Now the type of such knowledge Locke, like most of his contemporaries, found in the mathematical sciences, and more particularly in geometry. The perfect intellectual transparency, which appeared to him to be possessed and the c New Way of Ideas'* 5

both by the primary assumptions of these sciences and by their demonstrations, constituted his ideal of knowledge, and formed the standard by which he tested the worth of all our intellectual possessions. His view of knowledge, like that of Descartes, is throughout dominated by his conception of the mathematical sciences, the revival and development of which constituted the most striking intellectual achievement of the age in which he lived.

In this development of mathematics, and especially in the applications which were being made of mathematics to the solution of physical problems, there was much to suggest the need of an enquiry into the nature and limits of knowledge. Descartes had already put forward a generalisation of what he took to be the method of mathematics, which claimed to represent the true method of knowledge as such, and to reveal the very nature of intelligence; although even he had found in experience a refractory element .which refused to be reduced to the required form. The definite formulation of the principle of mechanical determination raised directly the question of the range of its applicability, in the answer to which the moral and religious as well as the purely scientific interests of man seemed to be closely involved. With the contemporary movement in England, of which the Cambridge Platonists were the typical representatives, which sought to place morality and the fundamental positions of Natural Theology upon a secure basis, by giving to them the form of a rational demonstration as unquestionable as any used by the mathematicians, Locke was in the fullest sympathy ; and among the motives which contributed to the production of the Essay, the leading place must be given to his desire to serve in this way what he regarded as the highest interests of mankind.

Keen as was his interest in the scientific discoveries of his day, he leaves no room for doubt that in his opinion the knowledge which is of greatest importance for man is that which relates to his duty, and to the existence of the Divine Being, whose law he conceived this duty to be. 'Our business here,' he declares, 'is not to know all things, but those which concern our conduct1.' 'Morality is the proper business and science of mankind in general2.' 'Morality and Divinity' are 'those parts of knowledge that men are most concerned to be clear in3.' And when Locke speaks of knowledge here, he means knowledge in the strict sense already explained. Least of all in matters of such weight would he be satisfied with anything short of complete certainty. The passage in the Essay which shows the greatest emotional warmth, in which the usually calm flow of its periods is broken by a series of almost rhetorical questions, is that in which he repudiates the idea that 'the greater part of mankind' are 'subjected to unavoidable ignorance in those things which are of greatest importance to them'; rejects with scorn the claim of the 'current opinions and licensed guides of every country' to furnish 'sufficient evidence and security,' where such great interests are at stake; and expresses his conviction that 'God has furnished men with faculties sufficient to direct them in the way they should take, if they will but seriously employ them that way, when their ordinary vocations allow them the leisure4.' For, ' how short soever their knowledge may come of an universal or perfect comprehension of whatsoever is,' men yet 'have light enough to lead them to the knowledge of their Maker, and the sight of their own duties5.' A note written by his

2 iv. 12. ii. 3 Epistle to the Reader.

friend, James Tyrrell, in a copy of the first edition of the Essay, informs us that the discussion between 'five or six friends,' which first led Locke to formulate his problem, was one 'upon the principles of morality and revealed religion.' But such explicit confirmation was hardly needed. For Locke himself tells us that it was because he suspected 'we began at the wrong end, and in vain sought for satisfaction in a quiet and sure possession of truths that most concerned us, whilst we let loose our thoughts into the vast ocean of being,' that he was led 'to take a survey of our understandings, examine our own powers, and see to what things they were adapted1.' It is for the security of knowledge itself, and not in its disparagement, that he would limit what he regards as the inordinate pretensions of our intellects. He would prevent men from 'letting their thoughts wander into those depths where they can find no sure footing,' because such a course can only tend 'to confirm them at last in perfect scepticism2.'

We may now sum up our account of the primary and main problem of the Essay, In it Locke undertakes the investigation of the nature and conditions of a knowledge which is at once absolutely certain, strictly universal, 'instructive' or synthetical, and 'real'; the consequent determination of the possible extent of such knowledge; and the examination of its distinction from and relation to other forms of cognition, which are deficient in some of the respects enumerated. While the mathematical sciences furnish us with the typical example of such knowledge, its most important contents are held to refer to the objects of our moral and religious consciousness.

§ 4. Of the problem as thus stated, moreover, Locke 1 1. 1. 7. 2 loc. ciu believed himself to have found a satisfactory solution; and it is to this solution, or some feature of it, that he draws attention on each of the occasions on which he claims originality or novelty for his work. Replying to the strictures of the Bishop of Worcester, he tells us, 'where if anywhere, that itch of vainglory was likeliest to have shown itself, had I been so over-run with it as to need a cure. It is where I speak of certainty, in these following words ..."I think I have shown wherein it is that certainty, real certainty consists, which, whatever it was to others, was, I confess, to me heretofore, one of those desiderata which I found great want of1.'" Again, 'Nobody, that I had met with, had, in their writings, particularly set down wherein the act of knowing precisely consisted... If I have done anything new, it has been to describe to others more particularly than had been done before, what it is they do, when they perform that action which they call knowing2.'

On two occasions in the Essay he speaks of more specific points in his theory as being in his opinion new. It is not, however, to the derivation of some complex idea from simple ideas of Sensation and Reflection that he refers us. The 'argument' which appeared to him 'new, and a little out of the way,' was one concerning 'the essences of mixed modes and relations3,' upon which his theory of the possibility of universal knowledge in ethics will be found to depend; while it was 'the reason and foundation' of the 'clearness or cogency' of self-evident propositions which, he tells us, nobody, to his knowledge, had ever before attempted to display4. At the same time he is careful to disclaim the intention of offering to mankind any new

1 Works, vol. iv. p. 136. The reference is to Essay iv. 4. 18.

method of attaining to knowledge. 'What I say of certainty was not to teach men a new way of certainty... but to endeavour to show wherein the old and only way of certainty consists1.' What Locke claims, then, to have done, in answer to the question which he propounded at starting, is to have detected by a process of analysis the essential nature of knowledge, and to have shown, by a survey of the contents of our cognitive consciousness, carried out in the light of this analysis, in what regions of human thought the requirements of knowledge, in the strict sense in which he uses the term, can be satisfied, and where we must rest content with the inferior forms of cognition which he designates 'opinion,' 'belief,' or 'probability.'