The principles of Christian apologetics, an exposition of the intellectual basis of the Christian religion, specially written for senior students

Front matter

V

7 PT"

THE WESTMINSTER LIBRARY

Preface

The study of the science of Apologetics is very necessary in these days of doubt and agnosticism. The fundamental principles which underlie all religious belief are daily called in question. And even if the urgent need of a reasoned grasp of the foundations of Faith did not exist, the interest of the subject of Apologetics, the large outlook upon life which it involves, the coherence of its parts and the cogency of its conclusions make it desirable that an examination into the principles of Theism should be an indispensable adjunct of Christian teaching.

The first step to take in the investigation of the claims of Natural Religion is to prove that an objective world exists, a world external to consciousness. The ground for this belief must be examined so as to justify the transit from consciousness to reality. In the process, one begins to realise, perhaps for the first time, the truth that there are many characteristics of the external world which our perceptive faculties are not keen enough to observe. At the same time, it can be shown that our perceptions, though not adequate, are true as far as they go, and this conclusion is sufficient for the validity of the well-known argument that contingent beings postulate the existence of a First Cause upon whom all contingent existences depend, the necessary personal Being, to whom we give the name of God. God exists. Man has been created by God. Man has been endowed with a spiritual soul — spiritual because for its existviii THE PRINCIPLES OF CHRISTIAN APOLOGETICS

encc and action it is independent of matter, and therefore persists after tlic death of the body. Man owes to God the debt of private and public acknowledgment and worsliip. Here in brief are the main theses of Natural Religion. Supported by this basis of Natural Religion, and aided by the application of the criteria of miracles and prophecy, the enquirer is led to the further conclusion that there is one and only one true form of Supernatural Revelation, namely Christianity. In the following chapters an attempt has been made to reproduce in English form the classical arguments which are set forth in text-books of Apologetics written chiefly in Latin, French and German. The aim has been to avoid as far as possible technical nomenclature, so that Senior Students of Secondary Schools may follow the trend of the discussion. If such students are called upon to unravel the intricacies of the Differential and Integral Calculus set for B.A. and B.Sc. degrees, it is surely not too much to expect that the metaphysical principles which are the support of Natural and Supernatural Religion should have some share of their attention.

In the development of the Apologetic argument, I desire to acknowledge my indebtedness to the Dominican work — Pere Garrigou-Lagrange's "Dieu, son existence et sa Nature,"^ and to another work of great merit, " Foi et Raison," written by M. le Chanoinc Valvekens.^ Whilst following these authors in the more formal and " scholastic " portions of their works, I have not hesitated to adopt another treatment if such appeared preferable. I desire to thank the Editor of the " Irish Theological Quarterly " for permission to republish some articles on Apologetic subjects contributed by me from

^ " Dieu, son existence et sa Nature," par P. Fr. R. Garrigou- Lagrange. Paris, Gabriel Beauchesne, 1915.

* "Foi et Raison" (Cours d'Apologetique), par M. le Chanoine Valvekens.

PREFACE ix

time to time. I desire also to thank Dr. Keith/ and his publishers, Messrs. Williams and Norgate, for the use of two illustrations which appear in Chapter IX, and the Rev. H. Thurston, S. J., for valuable suggestions and for the time and trouble involved in the correction of the proof sheets.

Regret has often been expressed that more use has not been made by writers on Apologetic subjects of the various branches of Natural Science — Physics, Astronomy, Biology, Geology, Anthropology — ^sciences which point to conclusions relevant to the theistic argument. Surely it is by endeavouring to comprehend the Natural as well as the Supernatural Revelation that foundations are more securely laid, and a better opportunity given of appreciating the harmony, beauty, and stability of the Divine edifice of Faith. Should any measure of success attend the present effort, should reflection be aided, doubt removed, reverence increased, I shall indeed be amply rewarded for my labour. But in the investigation of Divine Truth, we must not forget our limitations, so admirably expressed by the earliest of Christian Apologists: " O the depth of the riches of the wisdom, and the knowledge of God ! how incomprehensible are His judgments, and how unsearchable His ways ! " The " windows into the Absolute " permit us to see but " through a glass darkly." It is the trial of Faith. Presently we shall see " face to face."

T. J. W.

1 " The Antiquity of Man," by Dr. Keith.

Contents

Prefage Page rii

Chapter I Che External World

Objective value of sense impressions — Scepticism — Idealism — Critical Realism — Natural Realism — Primary and secondary qualities of bodies — Qualities of Sound — Qualities of Colour — Neo-Scholastic theses in regard to secondary qualities — Arguments in support of Neo-Scholastic view — The old scholastic teaching — Arguments in support of the same — Conclusion ......... i

Chapter II

I. Logical divisions of " Natural Religion " — Definition of

Vatican Council — Terms of oath against Modernism — Encyclical " Pascendi " . . . . . . . i6

II. Proofs which are " Scientific " — St. Anselm's ^ priori argument— Arguments a posteriori — Empirical Agnosticism — Hume — Mill — James — Comte and Littre — Idealistic Agnosticism— Kant, his categories and antinomies ... 20

III. How knowledge is acquired — First principles are intuitive — Rule and motive of certitude — In what sense there exists a subjective element in Knowledge — Bergson's philosophy of action ......... .24

IV. Transcendent value of primary notions and principles — How legitimately apphed to the Infinite — Kant's and Spencer's erroneous application of primary notions in their

uni vocal sense . . . . . . . . 2S

Chapter III

The five aspects of the metaphysical proof — General proof — Proof based on moving bodies — Efficient cause — Contingent Being — Degrees of Being — Manifestation of Order — Resume — Human opinion — " Les fanfarons petits-maltres de la Science " — The testimony of distinguished men in Science and Literature — Bacon, Pasteur, Bruneti^re, Huysmans, Bourget, Coppee, Kelvin — Dr. Dennert's chart ... 32 xii THE PRINCIPLES OF CHRISTIAN APOLOGETICS CHAPTER IV

The connotation of the word " Atheist " — Positivism and Agnogticism — Materialistic Monism — Materialistic Evolution — Spiritualistic Evolution — Lamarck — Darwin — Natural Selection— Mendel — Dc Vries — Phylogenetic tree of plants — Con- •lusion ......... Page 51

Chapter V A General View Of The Kature And Attributes Of God

I. Preliminary distinctions — Fundamental perfection of the

Divine Nature ........ 68

II. Attributes bearing directly upon the " being " of God — Unity and Simplicity — Truth — Perfection and Goodness — Infinity — Immensity — Immutability — Eternity — God is from the human standpoint invisible, incomprehensible, and withal cognoscible ......... 70

III. Attributes which bear upon Divine Work — Wisdom — Lore with its characteristics of Mercy and Justice . . .72

IV. Attribute of Infinite Power — Creation and Conservation — Divine Concursus — Miracles — Intimate Life of God . . 77

Chapter VI

I. Difficulties arising from the attributes of SimpMcity and Im-

mutability— Maimonides — Duns Scotus — Approved teaching — Perfections not virtually distinct one from another — Perfections between which there is a virtual distinction by reason of the different relations of creatures to God — Perfections virtually distinct independently of creatures ... 88

II. Difficulties arising from the existence of evil, physical and moral — Natural standpoint — Supernatural standpoint . . 95

III. Difficulties arising from the consideration of the Divine Nature as seen from the standpoints of Reason and Revelation .......... 105

Chapter VII Polytheism And Pantheism

I. Infinite Perfection of God involves His unity — Unity of pur-

pose in Nature witnesses to Unity of Creator — Unity of development manifested in our Solar System — Mosaic cosmogony and the geological record — Polytheism a decadent belief 108

II. Immanence and Transcendence — Personality — Illustration from the Human Nature of Christ — Pantheism the negation of Personality — God of Theism and the " Eternal Axiom "

of Taine 113

CONTENTS xili

Chapter VIII Che Nature Of Man

I. Spirituality of the Soul — Proofs — Materialistic objections —

Size of brain and niental ability .... Page ii6

II. Freedom of the Will — Liberty from constraint — Liberty of indifference — Proofs — Corollaries — Power of sinning an imperfection of free-will — Psychological power of habit — Determinism in its different forms . . . . .119

III. The Natural Law — Proofs of its existence — Primary, secondary and remote principles of the Moral or Natural Law — Promulgation and Sanction — Independent Morality . 124

Chapter IX Origin And Destiny Of Mam

I. Substantial union of Soul and body — The Oldest Human

ReUcs — Chart of Post-Tertiary times — NeoUthic Age — The Tilbury man — The first glimpse of Palseolithic times — Father McEnery of Torquay — Deluge at end of 4tli glacial period — Azilian culture and script — Magdalenian — Solutrean — Aurignacian cultures — Summary of discoveries of Later Pleistocene period — ilid-Pleistocene period — Mousterian Man — Abb-Ss A. and J. Bouyssonie and Bardon — Abbe Breuil — Early Pleistocene period — Pre-Chellean man — Large cranial capacity'— Dr. Gladstone on size of skull and mental power — Piltdown Skull — Antiquity of Man — Theological aspect — Unhkely assumption — Conclusion ..... 127

II. Origin of the Soul — Creative act of God — Unity of the human species — Unity of origin . . . . . . .141

III. Destiny of man — Immortality a consequence of spirituality — Need of adequate sanction for the Moral Law — Specific punishment a truth of Revelation . . . . .142

Chapter X

I. Necessity of Rehgion for the Individual — Utility of Rehgion

for the Individual — Necessity of Religion for Society — Cathohc and non-Catholic countries compared . . .144

II. Necessity and Utihty of Worship — Interior — Exterior — Social Worship . . . . . . . .150 xiv THE PRINCIPLES OF CHRISTIAN APOLOGETICS CHAPTER XI

I. China and Japan — Brahmanism and Buddliism — Persia,

Babylonia, Assyria, Syria — Arabia — Egypt — Greece and Rome — Primitive Races — Australian — African — American tribes ......... Pagt 153

II. The comparative method — Belief in a Supreme Being and Immortality of the Soul universal — Polytheism a declension from primitive Monotheism — Probable process of degeneration— St. Paul's anthropological doctrine — Census of the different forms of Religious behef . . . . -163

Chapter XII

I. Divine Revelation — Natural and Supernatural Orders —

Possibihty and congruity of the Supernatural Order — Mysteries — Absolute necessity of Revelation in regard to certain truths — Moral necessity of Revelation for the prompt, universal, certain and complete knowledge of the truths of Natural Religion — Criteria of Revelation . . . .167

II. Miracles — Nature of a miracle — Possibility — Possibihty of proving a miracle — The suggested commission of scientists — Miracles and Science — Suggestion, faith-heahng and hypnotism— The Divine causality can be established — Probative force of a miracle . . . . . . . .173

III. Prophecy — Nature of prophecy — Possibihty — True prophecies have taken place — Probative force of prophecy . 1 78

Chapter XIII

I. Rationahsm — Is Reason autonomous ? — Does Reason follow

an upward course ? — Rationalistic claim regarded from the standpoint of History and Philosophy . . . .181

II. Faith and Science — Apparent contradictions arise either from misapprehension of dogma or from confounding hypothesis with truth — How Reason helps Faith — How Faith helps Reason — Relation between Faith and Science . . .183

Chapter XIV

I. Three historical phases, Primitive, Mosaic, and Christian . 186

II. Historical Authority of the Gospels — Their integrity — Authenticity — Veracitj' . . . . . . .187

III. Divine authority of the Gospels — Nature of Inspiration — Aim and extent of Inspiration . . . . . .191

CONTENTS XT

Chapter XV The Divikity Of The Christian Faith

I. Attestation of Prophecy — Claim of Christ to be the Messiaa —

Confirmed by prophecies ...... Pagg 194

II. Attestation of Miracles — Miracles wrought on irrational beings — Wrought on human beings — Characteristics of their performance . . . . . . . . .198

III. Attestation of the Resurrection of Christ — Christ predicted His Resurrection in confirmation of His Mission — Witnesses

to His Resurrection ....... 200

Chapter XVI " Thou Art Christ, The Son Of The Living God "

I. " Thou art Christ " — Reahsation of Messianic Prophecy —

Detailed exposition of Messianic prophecies — Fulfilment . 204

II. " Thou art the Son of the Uving God " — Divinity of Christ proved from the Gospels — First group of texts — Criticism of

the same — Second group of texts ..... 209

III. Cumulative force of testimony — Resum6 .... 213

Chapter XVII

Schweitzer's book — Modernism described as Pantheism in philosophy and Unitarianism in Divinity — The Kingdom of God — " The advent of Messianic consciousness " — The eschatological theme — Pere Lagrange's critical analysis — Concluding remarks . . . . . . . . . .215

Chapter XVIII The Divinity Of The Christian Faith Directly Proved

I. Propagation — Quantitative — Qualitative — Supernatural Char-

acter— Objections ........ 226

II. Conservation — The fact — Supernatural character — Objections .......... 230

III. Transformation of the World — Fact — World before Christ and after Christ as regards the Individual, the Family and Society — Objections . . . . . . .232

IV. Heroism of the Christian Martyrs — Their number — Circumstances of duration, universality of the persecution, and the ferocity of the persecutors — The martyrs suffered for Rehgion — The true force of this argument — Objections — Resume in

the words of Lamy ........ 235

Bibliography ......... 241

Chapter I The External World

The student, who is accustomed to accept implicitly the testimony of the senses, finds at first the suggestion bewildering that sense-impressions do not represent accurately external qualities and objects. But once raised, the question, how far subjective states correspond to objective reality — how far our faculties may be trusted in the search after truth — is obviously of primary importance. Doubtless the student has many times watched a sunset with its gorgeous manifestation and changing panorama of colour ; many times too perhaps has he admired a landscape in which " meadow, grove and stream " seemed " apparelled in celestial light," or listened in time of storm to the roar of the angry waves as they lashed a rock-bound coast. Should science analyse the feast of colour into mere undulations of ether, resolve the roar of the angry ocean and the song of the lark into wavelengths of air ; should the redness of the rose, the whiteness of the lily, the verdure of the fields be merely a subjective vision, the objective world becomes indeed drab and uninspiring, and the gain in knowledge will never compensate for the loss of the " vision splendid," and the loss of Nature's orchestration with its sacramental suggestion of invisible power and beauty.

The attitude of students of philosophy in regard to the objective value of sense-impressions may be classified as threefold — the attitude of the Sceptic, of the idealist, and of the Realist.

First, the contention of the sceptic confronts us — the contention, namely, that objective knowledge is impossible, that between states of consciousness and their external causes there m.ay not be the -emotest resemblance, that it is impossible to bridge over the gulf which separates the subjective from the objective (if in truth the latter has any existoncc), that under the circumstances doubt is the truest wisdom :

There lives more faith in honest doubt, Behave me, than in half the creeds.

An examination, however, of this position shows inconsistency and indeed contradiction. The assertion " doubt is the truest wisdom " is put forward either as {a) a sure principle, or (6) as a doubtful one, or (c) as neither certain nor doubtfuh If the first supposition be taken, it is clear that a positive and certain principle is laid down in direct contradiction to the fundamental tenet that " nothing is certain," and in the second and third hypotheses the element of doubt is fatal to the value of the statements. Nay, the expression of an opinion on the part of the sceptic involves at least three contradictions : (i) he assumes as certain his own existence ; (2) he accepts the truth of the principle of contradiction inasmuch as this principle underlies every statement ; and (3) he draws a distinction between knowledge and ignorance, between certainty and doubt. Scepticism stands selfcondemned.

Idealism is a modified form of scepticism. Idealists admit the certainty of states of consciousness. The " monistic idealists " recognise the unity of the subject which experiences the states of consciousness in contradistinction to the " pluristic idealism " of Hume and others who held that the succession of conscious states are so many separate experiences without an underlying unity of subject. Monistic idealism is subdivided according as the percipient subject is believed to be the individual " ego " (subjective monistic idealism) ; whereas if the percipient subject be a world mind (universal consciousness, of which the individual mind forms but a manifestation) another form of idealism emerges, objective monistic idealism, of which Fichte, Hegel and Schelling were the chief supporters. Berkeley, bishop of the Irish diocese of Cloyne, taught that God acts upon our sensitive powers so as to produce the appearance of an external world, whereas the only real objective beings are spirits. This form of idealism is no longer held, nor did Berkeley ever succeed in reconciling the deceitful appearance of phenomena with the truthfulness of God. Perhaps the most striking example of an idealistic system logically developed is that of Kant. He attributes to the human mind three main cognitive faculties — perception, understanding and reason. Each of these faculties contains forms of thought by the application of which to the materials given in the senses knowledge in the scientific sense is produced. Perception has two forms — time and space. Understanding has twelve categories under four general heads — quantit\', qualit5^ relation, modality ; and reason seeking after unity places before itself ideals in which the phenomena of consciousness, of the outer world and of possible existence are summed up. Hence the ideals of the soul, of the universe, and of God. And these ideals are not objects of actual and positive knowledge, but regulative principles which guide reason in its search after highest truth. It will be sufficient in this chapter to point out two objections fatal to Idealism. First it misapprehends the true meaning of Knowledge. The mere succession of mental phenomena can never furnish materials for scientific knowledge, unless the mind can grasp the causal relations which bind them together. The discovery of the planet Neptune is a case in point. Leverrier and Adams both noted irregularities in the orbit described by Uranus which led them finally to postulate the existence of another planet. Here surely was a suggestion, the truth of which depended upon the reality of the force of attraction, the respective positions of the planets and other objective considerations. And though

Neptune had never been recognised as belonging to our solar system and was invisible to the naked eye, the astronomer relying upon the objective truth of physical principles was able to indicate the portion of the heavens where the new planet would be seen, if suitable optical means were employed. Physical science and Idealism are not compatible. The second objection is equally strong : every form of Idealism questions the truth of the information derived from the perceptive faculties, and thus logically leads to Scepticism.

Some students of philosophy take up a position midway between Idealism and Natural Realism. Tliey are known as Critical Realists. Their system rests upon a fundamental principle which may be stated thus : states of consciousness are primarily known and from them by aid of the principle of causality, the inference to the objectivity of the external world is made. But the question arises how can the truth of the law of causality be known unless we are assured of the real existence of cause and effect which our sensitive faculties perceive ? The intuitive principle of causality is recognised by the intellect from the materials furnished bj^ sense-perceptions ; so that to invoke the aid of causality in order to establish the objectivity of sense-perceptions is a flagrant instance of the logical fallacy known technically as " petitio principii," or in more familiar language the fallacy of the " vicious circle." But even if the truth of the principle of causality be granted, the only inference which can be made is that there is an external cause of sensitive cognition, but of the nature of the cause nothing is known. Critical Realism is thus seen to be practically identical with the phenomenalism of Kant alluded to above.

Special attention must now be given to an examination of the chief principles of Natural Realism, the most fundamental and important of which asserts that we have an immediate perception of the outward world, that sense-impressions are not directly perceived but determJne the sense to the immediate perception of the outward object. This is the complementary truth which, overlooked by Idealists, vitiates their conclusions. No matter how logical their reasoning may be, if it sets out from faulty premises, the harvest of error will be more abundant in accordance with the efficiency of the logical process.

Scholastic writers distinguish between the primary and secondary qualities of bodies : the primary qualities, extension, movement, etc., capable of being tested by more than one sense are called " sensibilia communia," whereas each of the secondary qualities appeals to one particular sense, colour to the eye, sound to the ear, odour to the nose, taste to the palate, sense of resistance, of heat and cold, to the touch. Hence a secondary quality is appropriately named " sensibile proprium." Students of Natural Science have succeeded in making interesting discoveries regarding the nature and causes of secondary qualities of bodies. Sound, for instance, has been analysed as the energy of a body propagated by air — an energy which is perceived when the airwaves reach the ear. There are three qualities of sound v/ell known to students of the subject : (i) intensity (loudness), which is due to the amplitude of the vibration ; (2) pitch, due to the length of the vibrating body, and consequently to the number of vibrations per second ; and (3) timbre or quality of tone. " Doh," for instance, sounded on a piano may have the same intensity and the same pitch as " Doh " sounded on a violin, but the two notes will differ markedly in timbre. The strings both of the piano and violin vibrate as whole strings, but there are minute vibrations of portions of the strings forming " overtones," which, coalescing with the principal tones, give to each note its peculiar quality. The number of vibrations per second of a note compared with those of an octave higher gives the proportion 1:2. The vibrations per second of C and G are as 2:3. Those of C and F are as 3 : 4. The number of vibrations of F, A, and C are as 4 : 5 : 6.

Interesting discoveries and speculations have been made also in regard to Colour. The energy of the molecules of a body (e.g. the Sun) propagated by transverse vibrations of ether are said to be the fundamental cause of colour, and the perception by the eye of this undulatory energy constitutes the sensation of colour. It is well known that tlic light of the Sun may by means of the spectrum be split up into seven different colours — red, orange, yellow, green, blue, indigo, violet. The analogy between the seven notes of the musical scale, dch, ray, me, fcJi, sch, Idi, te, and the seven spectral colours is striking and suggestive. It has been estimated that the vibrations per second of the red rays of the spectrum are about 460 billions, and those of the violet '■ays 670 billions. Whence it appears that colour is the " pitch " of light. Again we are assured that when sunlight falls upon a body — say upon the red petals of a rose — owing to their molecular constitution the petals absorb all the rays except the red which are reflected to the eye. In case of black objects all the ra3'S are absorbed, whilst all the rays are reflected from white surfaces. And the conclusion is formed generally by scientists that colour exists in bodies in the sense that they possess a certain selective or absorptive power. Colour exists fundamentally or causally in the external object, and exists in its formal character of colour only in the eye.

Many waiters of the Neo-scholastic school accept the general teaching of scientists in regard to the subjectivity of secondary qualities of bodies and justify their acceptance by the following arguments to which we shall endeavour to do the fullest justice. Our criticism of this aspect of Natural Realism will follow in due course.

A. Thesis in Regard to Sound

If the truth of perception requires that in the vibrating body or air, sound should exist objectively as it is perceived, then it must exist objectively with the same intensity, pitch and timbre wherewith it is perceived.

But that is impossible.

Therefore the truth of the perception does not require, etc.

The minor is proved as follows :

{a) Intensity. Loudness or intensity decreases as the square of the distance. Two men placed at different distances from the sounding body perceive different intensities. But if they both hear the sound as it exists in the bod5^ there must be different intensi.ies there at the same time.

{b) Pitch. A simple diagram will illustrate the argument in this case.

A S Ai

Let S represent a railway station. A indicates an approaching train. The pitch of the engine's whistle when first heard as it approaches the station is recognised to be sch (G), but when the whistle is sounded in the station preparatory to departure, the pitch is fah (F), and as the train recedes in the direction A\ the pitch sinks to m^e (E). From the scientific standpoint there is a satisfactory explanation. The airwaves created by the whistle of the approaching train, falling with accelerated frequency upon the ear, raise the pitch, whilst falling with less frequency as the train recedes, the pitch is lowered. And many writers of the Neo-scholastic school appeal to this experiment as showing that sound does not exist formally outside the sense. " The engine-driver," they say, " hears the note fcJi (F) all the time. The listener at the station hears sch, then fah and fina.Uy me. If sound exists objectively as heard, we have contradictory and confusing results."

(c) Timbre. The quality of a tone can be artificially produced by the vibrations of a number of distinct bodies (tuning forks). In this case of artificial production no individual body can lay claim to the formal sound. But the quality of a note is due, as explained above, to the overtones which come from segments of the string and which correspond to the tuning forks. In no case then can the particular formal sound (timbre) exist objectively.

B. Thesis in Regard to Colour

The Neo-scholastics for the most part accept also the subjectivity of colour. " Colour exists fundamentally in the object and formally in the sense." And the following arguments are advanced in support of this thesis.

{a) Argument based on tlie " interference " of light. In the case of a soap-bubble if observers be differently stationed, one notes that a certain part of the bubble is red, anotlier judges that same part to be green, whilst a third concludes that it is violet. It is contended that if formal colour existed objectively, each observer would see the same colour in the same place.

(6) Argument based on mixture of colours. Blue and yellow pigments produce greenish colour. Now the green (if formally present) must inliere either in the aggregate of the particles or in the particles themselves. Not in the aggregate of the particles, which is a mixture of blue and yellow ; and not in the particles themselves, which have their own respective colours. The colour of the aggregate, therefore, cannot be explained on the hypothesis of " formal " colour in the object.

(c) Newton's disc. The experiment with Newton's disc is well known. It depends on the fact that the eye requires J of a second to discriminate colours. The spectral colours on the disc rotated rapidly produce the sensation of white colour. Formal colour is therefore claimed to be subjective.

(d) Change of Light. Finally the change of colour produced by change of light points also to subjectivity. Blue and green, distinguisliable in daylight, appear in both cases to be green in candle light.

An endeavour has been made to state the arguments for the subjectivity of fonnal sound and formal colour in the fairest way, but this teaching is open to the serious objection that it favours Idealism. If in truth secondary qualities of bodies are not objective, the inference follows that even primary qualities lose their claim to objectivity, since they are revealed to us by secondary qualities. The extension of a body is known through its colour, and if there is deception in regard to colour, the deception affects the extension. Indeed both Berkeley and Kant deduced tiieir idealistic views from the supposed subjectivity of secondary qualities.