THE THEORISTS OF KNOWLEDGE
LOCKE, BERKELEY, HUME, KANT.
Epistemology, or theory of knowledge, did not begin in modern times. Among
the Greeks it goes back, at least, to Empedocles, and figures largely in
the programmes of the later schools. And Descartes's universal doubt seems
to give the question, How can we be sure of anything? a foremost place in
speculation. But the singular assurance with which the Cartesian
metaphysicians presented their adventurous hypotheses as demonstrated
certainties showed that with them the test of truth meant whatever told for
that which, on other grounds, they believed to be true. In reality, the
thing they called reason was hardly more than a covert appeal to authority,
a suggestion that the duty of philosophy was to reconcile old beliefs with
new. And the last great dogmatist, Leibniz, was the one who practised this
method of uncritical assumption to the utmost extent.
LOCKE.
It is the peculiar glory of John Locke (1632-1704) to have resumed that
method of doubt which Descartes had attempted, but which his dogmatic
prepossessions had falsified almost at the first start. This illustrious
thinker is memorable not only for his services to speculation, but for the
example of a genuinely philosophic life {66} entirely devoted to truth and
good--a character in which personal sweetness, simplicity, and charm were
combined with strenuous, disinterested, and fearless devotion to the
service of the State. Locke was a Whig when Whiggism meant advanced
Liberalism in religion and politics, and when _that_ often meant a choice
between exile and death. Thus, after the fall of his patron, Lord
Shaftesbury, the philosopher had to take refuge in Holland, remaining there
for some years, lying hid even there for some time to escape an extradition
order for which the Government of James II. had applied. It was in Holland
that he wrote the _Essay Concerning Human Understanding_.
This revolutionist in thought was no solitary recluse, but, in the best
sense, a thorough man of the world. Educated at Westminster and Christ
Church, he had, in the German poet's phrase, the supreme happiness of
combining the seriousness of an enthusiast with the sagacity of a
statesman, so that great statesmen recognised him as one of themselves.
With the triumph of the Whig cause at a time when diplomacy demanded the
utmost tact and skill, it was proposed to send Locke as Ambassador to the
Court of Brandenburg, and, as that would not have suited his sober habits,
to the Court of Vienna. Weak health obliging him to decline this also, he
received office in the Ministry at home, taking a department where business
talents were eminently required. In that capacity he bore a leading part in
the restoration of the coinage, besides inspiring the Toleration Act and
the Act for Unlicensed Printing. Even the wisest men make mistakes; and it
must be noticed with regret that Locke's theory of toleration excluded
Roman Catholics on the one side and atheists on the other--the former
because their {67} creed made persecution a duty, the latter because their
want of a creed left them no sanction for any duties whatever. To say that
Locke had not our experience does not excuse him, for in both cases the
expediency of toleration can be proved _a priori_. Romanists must be
expected to suppress a heresy whose spokesman declares that when he has the
power he will suppress their Church; and, if atheists are without moral
principle, they will propagate, under cover of orthodoxy, negations that
they are not allowed openly to profess.
Locke was brought up by a Puritan father; and, although in after life he
wandered far from its doctrinal standards, he no doubt always retained a
sense of that close connection between religion and morality which
Puritanism implies. Telling about the train of thought that started his
great Essay, he refers it to a conversation between himself and some
friends, in which they "found themselves quickly at a stand by the
difficulties that rose on every side;" and, according to an intimate friend
of his, the discussion turned "on the principles of morality and revealed
religion." It then occurred to him that they should first ascertain "what
objects their understandings were or were not fitted to deal with." And the
mottoes prefixed to the essay prove that the results were of a decidedly
sceptical cast. Indeed, his successors, though not himself, were destined
to develop them into what is now called Agnosticism.
We have further to note that, while his Continental rivals were
mathematicians, our English philosopher never went deeply into mathematics,
but was by calling a physician. In this he resembles Aristotle and Sextus
Empiricus among the Greeks; and so it is quite in order that, with the same
sort of training, he should {68} adopt Aristotle's method of experience as
against Platonic transcendentalism, and the sceptical relativism of Sextus
as against the dogmatism of the schools.
Locke begins his essay with a vigorous polemic against the doctrine of
Innate Ideas. The word "idea," as he uses it, is ambiguous, serving to
denote perceptions, notions, and propositions; but this confusion is of no
practical importance, his object being to show that all our knowledge
originates in experience; whereas the reigning belief was that at least the
first principles of knowledge had a more authoritative, if not a mystical,
source. Hobbes had been beforehand with him in deriving every kind of
knowledge from experience, but had been content to assume his case; whereas
Locke supports his by a formidable array of proofs. The gist of his
argument is that intellectual and moral principles supposed to be
recognised by all mankind from their infancy are admitted only by some, and
by those only as the result of teaching.
As we saw, the whole inquiry began with questions about religion and
morality; and it is precisely in reference to the alleged universality and
innateness of the belief in God and the moral law that Locke is most
successful. And the more modern anthropology teaches us about primitive
man, the stronger becomes the case against the transcendental side in the
controversy. Where his analysis breaks down is in dealing with the
difficult and important ideas of Space, Time, Substance, and
Causality--with the fatal result that such questions as, How is experience
itself possible? or, How from a partial experience can we draw universal
and necessary conclusions? find no place in his theory of knowledge. Of
course, his contemporaries are open to the same {69} criticism--nor,
indeed, had the time come even for the statement of such problems.
Meanwhile, the facility with which the founder of epistemology accepts
fallacies whence Spinoza had already found his way out shows how little he
was master of his means. According to Locke, it is "a certain and evident
truth that there is an eternal, most powerful, and most knowing being,
which whether anyone will please to call God it matters not." On
examination the proof appears to involve two unproved assumptions. The
first is that nothing can begin to exist without a cause. The second is
that effects must resemble their causes. And from these it is inferred that
an all-powerful being must have existed from all eternity. The alternative
is overlooked that a succession of more limited beings would answer the
purpose equally well, while it would also be more consistent with our
experience. But a far more fatal objection to Locke's theism results from
his second assumption. This, although not explicitly stated, is involved in
the assertion that for knowledge such as we possess to originate from
things without knowledge is impossible. For, on the same principle, matter
must have been made by something material, pain by something that is
pained, and evil by something that is evil. It would not even be going too
far to say that by this logic I myself must have existed from all eternity;
for to say that I was created by a not-myself would be to say that
something may come from nothing.
We have seen how Locke refused toleration to atheists on the ground that
their denial of a divine lawgiver and judge destroys the basis of morality.
He did not, like Spinoza, believe that morality is of the nature of things.
For him it is constituted by the will of God. Possibly, if pressed, he
might have explained {70} that what atheism denies is not the rule of
right, but the sanction of that rule, the fear of supernatural retribution.
Yet being, like Spinoza and Leibniz, a determinist, he should have seen
that a creator who sets in motion the train of causes and effects
necessarily resulting in what we call good or bad human actions has the
same responsibility for those actions as if he had committed them himself.
To reward one of his passive agents and to punish another would be grossly
unjust and at the same time perfectly useless. But how do we know that he
will, on any theory of volition, reward the good and punish the bad?
"Because we have his word for it." And how do we know that he will keep his
word? "Because he is all-good." But that, on Locke's principles, is pure
assumption; and God, being quite sure that _he_ has no retribution to fear,
must be even more irresponsible than the atheist.
The principle that nothing can come from nothing, so far from proving
theism, leads logically either to pantheism or to a much more thorough
monadism than the system of Leibniz. And, metaphysics apart, it conflicts
with a leading doctrine of the essay--that is the fundamental distinction
between the primary and the secondary qualities of matter. We think of
bodies as in themselves extended, resisting and mobile, but not in
themselves as coloured, sonorous, odorous, hot, cold, or sapid. They cause
our special sensations, but cause them by an unknown power. Again we
perceive--or think we perceive--both primary and secondary qualities in
close union as properties of a single object, and this object in which they
jointly inhere is called a substance. And to the question, What is
substance? Locke admits that he has no answer except something we know not
what. He has returned to the agnostic standpoint of the {71} Cyrenaic
school. This something, for aught we know, might have created the world.
Continental historians regard the whole rationalistic movement of the
eighteenth century, or what in Germany is called the Enlightenment
(Aufklaerung), as having been started by Locke. But the sort of arguments
that he adduces for the existence of a God prove that in theology at least
his rationalism had rather narrow limits. Both his theism and his
acceptance of Christianity on the evidence of prophecy and miracles show no
advance on medieval logic. In this respect Spinoza and Bayle (1622-1709)
were far more in line with the modern movement. Still, assuming scripture
as an authoritative revelation, Locke shows that, rationally interpreted,
it yields much less support to dogmatic orthodoxy than English Churchmen
supposed. And whatever may have been the letter of his religious teaching,
there can be little doubt that the English Deists, Toland, Shaftesbury, and
Anthony Collins, represented its true spirit more faithfully than the
philosopher himself.
Representative government and the subordination of ecclesiastical to
secular authority--or, better still, their separation--are both good things
in themselves and favourable conditions to the life of reason. Another
condition is that children should be trained to exercise their intelligence
instead of relying blindly on authority. In these respects also Locke's
writings acted powerfully on the public opinion of the next century,
especially through the agency of French writers; France, as Macaulay justly
claims, being the interpreter between England and the world. Our present
business, however, is not with the diffusion but the development of
thought, and to trace this we must return to British philosophy. {72}
BERKELEY.
George Berkeley (1684-1753) was born and educated in Ireland. The fact is
of no racial or national importance, but interests us as accounting for his
having received a better training in philosophy than at that time was
possible in England. For the study of Locke, then proscribed at Oxford, had
already been introduced into Dublin when Berkeley was an undergraduate
there; and it was as a critical advance on Locke that his first
publication, the _New Theory of Vision_ (1709), was offered. Next year came
the epoch-making _Principles of Human Knowledge_, followed in 1713 by the
more popular _Dialogues_. At twenty-nine his work was done, and although he
lived forty years longer, rising to be a Bishop in the Irish Church, after
projecting a Christian Utopia for the civilisation of the North American
Indians that never came to anything, and practising "every virtue under
heaven," he made no other permanent contribution to thought.
Berkeley is at once a theorist of knowledge and a metaphysician, combining,
in a way, the method of Locke with the method of Descartes and his
successors. The popular notion of his philosophy is that it resolved the
external world into a dream, or at least into something that has no
existence outside our minds. But this is an utter misconception, against
which Berkeley constantly protested. His quarrel was not with common sense,
but with the theorists of perception. To understand this we must return for
a moment to Locke's teaching. It will be remembered in what a tangle of
difficulties the essay had left its author. Matter had two sets of
qualities, primary and secondary, the one belonging to things in
themselves, the other existing only {73} in our minds; yet both somehow
combined in real substances independent of us, but acting on our senses.
Substance as such is an unknown and unknowable postulate; nevertheless, we
know that it was created by God, of whom our knowledge is, if anything,
inconveniently extensive. Now Berkeley, to find his way out of these
perplexities, begins by attacking the distinction between primary and
secondary qualities. For this purpose his _Theory of Vision_ was written.
It proves--or attempts to prove--that extension is not a real attribute of
things in themselves, but an intellectual construction, or what Locke would
have called an "idea of reflection." Till then people had thought that its
objectivity was firmly established by the concurrent testimony of two
senses, sight and touch. Berkeley shows, on the contrary, that visible and
tangible extension are not the same thing, that the sensations--or, as he
calls them, the ideas--of sight and touch are two different languages whose
words we learn by experience to interpret in terms of each other without
their being necessarily connected. A man born blind would not at first
sight know how to interpret the visual signs of distance, direction, and
magnitude; he would have to learn them by experience. These, in fact, are
ideal relations only existing in the mind; and so we have no right to
oppose mind as inextended to an extended or an external world.
Having thus cleared the ground, our young idealist proceeds in his next and
greatest work, _Of the Principles of Human Knowledge_, to attack the
problem from another side. The world of objects revealed through sensation
and reflection is clearly no illusion, no creation of our own. We find it
there, changing, when it changes, without or even very much against our
will. {74} What, then, is its origin and nature? Locke's view, which is the
common view, tells us that it consists of material bodies, some animated
and some not. And matter, the supposed substance of body, is made known to
us by impressions on our organs of sense. But when we try to think of
matter apart from these sensible qualities and the relations between them
it vanishes into an empty abstraction. Now, according to Berkeley there are
no abstract ideas--_i.e._, no thoughts unassociated with some mental image
besides a mere word; and Matter or inanimate substance would be such an
idea, therefore it does not exist. There is nothing but mind and its
contents--what we call states of consciousness, what Locke and Berkeley
called ideas. Whence, then, come the objects of our consciousness, and
whither do they go when we cease to perceive them? At this point the new
metaphysical system intervenes. Berkeley says that all things subsist in
the consciousness of God, and by their subsistence his existence is proved.
The direct apprehension of a reality that is not ourselves only becomes
possible through what would be called in modern language a subjective
participation in the divine consciousness, more feebly reflected, as would
seem, in the memories, imaginations, and reasonings of our finite minds.
In pursuing these wonderful speculations Berkeley deviated widely from the
direct line of English philosophy, and it is difficult not to believe that
the deflection was determined by the influence of Malebranche, especially
when we find that the writings of the Oratorian Father were included in his
college studies. Moreover, a parallel line of idealistic development
derived from the same source was evolving itself at {75} the same time in
English thought. John Norris (1657-1711), a correspondent of the Platonist
Henry More, an opponent of Locke, and a disciple of Malebranche, had
himself found an enthusiastic admirer in Arthur Collier (1680-1732), whose
_Clavis Universalis_ professed to be "a demonstration of the _non-existence
or impossibility of an external world_" (1713). Both Norris and Collier,
like Malebranche and Berkeley, were Churchmen; but so strong was the drift
towards idealism that Leibniz, a layman and a man of science, contributed
by his Monadology to the same current. Malebranche neither was nor could he
be a complete idealist in the sense of denying the reality of matter; for
the dogma of transubstantiation bound him, as a Catholic, to its
acceptance, while Berkeley, Collier, and Leibniz, as Protestants, were
under no such obligation. His idealism agreed more nearly with the
Neo-Platonic doctrine of Archetypes in the divine Reason among which Matter
was one. On the other hand, Berkeley probably borrowed from him the notion
of a direct contact with God, the difference being that with the Cartesian
it is conceived as an objective vision, with Locke's disciple as (if the
expression may be permitted) a subjective con-consciousness. Leibniz,
again, while abolishing Matter, retains an external world composed indeed
of spirits and so far immaterial, but existing independently of God.
All these systems involve the negation of two fundamental scientific
principles. The first is that every change must be explained by reference
to an antecedent change to which it bears a strict quantitative relation.
The second is that no particular change can be referred to another change
as its necessary antecedent unless it can be shown by experience that a
precisely similar {76} couple of changes are, in fact, always so connected.
Let me illustrate these principles by an example. I leave a kettle full of
cold water on the fire, and on returning after a sufficient interval of
time I find the water boiling. Had I stayed by the fire and watched the
process, my kettle would--a popular proverb to the contrary
notwithstanding--have certainly boiled as soon, but also no sooner for
being helped by my consciousness. The essential thing is that energy of
combustion in the fire should be turned into energy of boiling in the
water. Now, what is Berkeley's interpretation of the facts? Fire, kettle,
water, and ebullition are what in his writings are called "ideas"--_i.e._,
phenomena occasionally in my mind, but always in God's mind. And according
to this view the necessary antecedent to the boiling of the water is not
the fire's burning, but God's consciousness of its burning, his perception
being the essence of the operation. But it is proved by experience that
neither my perception nor anyone else's ever made a single drop of water
boil. In other words, perception is not in this instance a _vera causa_.
Why, then, should the perception of any other mind, however exalted, have
that effect?
Nor is this all. How does Berkeley know that God exists? Because, he says,
to exist is to be perceived, and therefore for the universe to exist
implies a universal Percipient. But he got the idea of God from other men,
who certainly did not come by it as a generalisation from their
perceptions; they got it by generalising from their voluntary actions,
which do produce the changes that perception cannot produce. It will be
said that volitions and the feelings that prompt them exist only in
consciousness. In whose consciousness? In that of a spirit. And what is
spirit apart from {77} sensation, thought, feeling, and volition? Simply
one of those abstract ideas whose existence Berkeley himself denied.
HUME.
The next step in the evolution of English thought was to consist in a
return to Locke's method, involving a complete breach with
seventeenth-century Platonism, and with the Continental metaphysics that it
had inspired. This decisive movement was effected by one in whom German
criticism has recognised the greatest of all British philosophers. David
Hume (1711-1776) was born and bred at Edinburgh, which also seems to have
been through life his favourite residence. But his great work, the
_Treatise on Human Nature_, was written during a stay in France, between
the ages of twenty-three and twenty-six. Thus his precocity was even
greater than Berkeley's. Indeed, such maturity of thought so early reached
is without a parallel in history. But Hume's style had not then acquired
the perfection--the inimitable charm, Kant calls it--of his later writings;
and, whether for this or for other reasons, the book, in his own words,
"fell dead-born from the press." In middle life the office of librarian of
the Advocates' Library at Edinburgh gave him access to the materials for
his _History of England_, which proved a source of fame and profit. A
profound historical scholar, J. S. Brewer, tells us that Hume "possessed in
a pre-eminent degree some of the highest excellences of a historian." Other
historians have treated their subjects philosophically; he furnishes the
sole instance of a great speculative genius who has also produced a
historical masterpiece of the first order. But morally it is a blot on his
fame. It is sad that a philosopher should have deliberately perverted the
truth, that one who has {78} [Illustration: DAVID HUME.] performed
priceless services to freedom of thought should have made himself the
apologist of clericalising absolutism, and, still more, that a master of
English played this part to some extent through hatred of the great English
people engendered by disappointed literary ambition. It may be mentioned,
however, as a possible extenuation that towards the middle of the
eighteenth century the highest English ability had thrown itself, with few
exceptions, on the Tory side. It must be mentioned {79} also that in
private life Hume's character was entirely admirable--cheerful, generous,
and gentle, without a frailty and without a stain. His opinions were
unpopular; but his life offered no handle for obloquy, although his
studious retirement was more than once exchanged for the responsibilities
of political office, and the freedom from pedantry so conspicuous in his
writings bears witness to habits of well-bred social intercourse.
Hume's philosophy is best understood when we consider it as, in the first
place, a criticism of Berkeley, just as Berkeley's had been a criticism of
Locke. It will be remembered that the founder of subjective idealism
discarded the notion of material substance as an "abstract idea," an
unintelligible figment devoid of any sensuous or imaginative content. The
only true substances are the subjects of what we call experience
communicating through sensation with God, the infinite spirit whose eternal
consciousness is reality itself. Hume applied the same tests to spiritual
substance, and found that it equally disappeared under his introspective
analysis. He begins by dividing the contents of consciousness into two
classes, impressions and ideas--the second being copies of the first, and
distinguished from them by their relative faintness. Now, from these
perceptions (which he called thoughts) Descartes had passed by an immediate
inference to the ego or self, which he affirms as the primary fact of
consciousness, using it as a basis for sundry other conclusions. But Hume
stops him at once, and will not grant the existence of the metaphysical
self--that is, a simple and continued substance, as distinguished from
particular states of consciousness. We are, he declares, "nothing but a
bundle of different perceptions, which {80} succeed each other with an
inconceivable rapidity, and are in a perpetual flux and movement." "There
is properly no _simplicity_ in it [the self] at one time, nor _identity_ in
different [times]; whatever natural propensity we may have to imagine that
simplicity and identity." So much being assumed, Berkeley's whole argument
for a new theology founded on subjective idealism is bound to collapse, as
also is the argument for natural immortality derived from the supposed
simplicity and identity of the thinking substance.
Modern critics have rightly insisted, as against Hume, that isolated
perceptions without a self are abstractions not less unintelligible than a
self without perceptions. But the metaphysical argument for human
immortality has not benefited by this more concrete interpretation of
epistemology; and probably Hume was really more interested in destroying
this than in maintaining the sceptical paradox which does not recur in his
later writings.
A word must be added about Hume's division of perceptions into impressions
and ideas. The point left out of sight in this analysis is that impressions
of sense habitually find their reflexes not in revived sensations, but in
expressions, in motor reactions which, with human beings, mostly take the
form of words uttered or thought. These, no doubt, are associated to some
small extent with revived sensations; but they are more commonly grouped
with other words, with movements of the limbs, and with actions on the
material or human environment of the percipient. Such expressions are
incomparably easier to revive in memory, imagination, or expectation than
the impressions that originally excited them; and, indeed, it is in
connection with them that such revivals of sensation {81} as we actually
experience take place. And it is probable that to this active side of our
consciousness that we may trace those associative processes which Hume
studies next in his analysis of human knowledge.
Putting aside principles of doubtful or secondary value, the relations
between states of consciousness that first offer themselves to view are,
according to Hume, Co-existence and Succession (united under the name of
Contiguity), Resemblance, and Causation. It is with the account he gives of
this last category that his name is inseparably associated, for from it all
subsequent speculation has taken rise. Yet primarily he seems to have had
no other object in view than to simplify the laws of knowledge by resolving
one of them into a particular case of another, and thus reducing his three
categories to two. The relation of cause and effect, he tells us, is no
more than a certain relation between antecedent and consequent in time
where the sequence is so habitual as to establish in our minds a custom of
expecting the one whenever the other occurs. The sequence is not necessary,
for one can think, without any self-contradiction, of a change which has
not been preceded by another change; nor is it, like the truths of
geometry, something that can be known _a priori_. Without experience no one
could tell that bread will nourish a man and not nourish a lion, nor even
predict how a billiard-ball will behave when another ball strikes it.
Should it be objected that the _a priori_ knowledge of a general principle
need not involve an equal knowledge of nature's operations in particular
cases, Hume would doubtless reply by saying that there is no abstract idea
of causation apart from its concrete exemplifications.
It is possible to accept Hume's theory in principle {82} without pledging
oneself to all his incidental contentions. Causation, as a general law, may
be known only by experience, whether we can or cannot think of it as a pure
abstraction. And we may interpret it in terms of unconditional antecedence
and consequence, while discarding his apparent assumption of an inscrutable
connection between the two; a mysterious necessity for the production of
the one by the other, for which it is felt that a reason exists, but for
which our reason cannot account. It is inconceivable that our knowledge of
any given sequence could be increased, except by the disclosure of
intermediate sequences, making their continuity, in space and time, more
absolute than we had before perceived, until the whole process has been
resolved into a transference of momentum from one molecule to another--a
change for which, according to Hume, no reason can be given. Nor, on his
principles, would it help us to explain such transferences by bringing them
under the law of the Conservation of Energy. For, although this would be a
great triumph for science, his philosophy demands a reason why the quantity
of energy should remain unalterable for ever.
It is a mistake, shared by Hume with his opponents, to suppose that the
common sense of mankind ever saw more than invariable sequence in the
relation of cause and effect, or ever interpolated a mysterious power
between them. In the famous verse, "Let there be light, and there was
light," it is the instantaneity of succession, not the interpolation of any
exerted effort, that so impresses the imagination. And when Shakespeare
wants to illustrate logical compulsion in conduct, his reference is to an
instance of invariable succession:-- {83}
This above all,--to thine own self be true;
And it must follow, as the night the day,
Thou canst not then be false to any man.
Indeed, I think it will be found on examination that when we associate the
idea of power, or of necessity, with causal sequences, it is not in
connection with a case of causation here and now, but rather in reference
to similar effects that may be expected from the same cause elsewhere or at
another time. And that "custom," by which Hume seeks to explain our belief
in the "power" of the cause to produce its effect as well as the
"necessity" of the connection between them, rather acts negatively by
eliminating all other antecedents as possible causes than positively by
setting up a habit of thinking about a particular antecedent and consequent
at the same time. And that is why a burnt child needs no repetition of the
experiment to be convinced that contact with fire was the cause of its
pain. The very novelty of the experiment was enough to eliminate any
explanation other than that of contact with the flame.
The child, as it grows older, may learn to speak of the fire as having a
power to burn. But that merely means, "if I touch it, it will burn me--or
light paper if I hold the paper to it." Power, in fact, is incomplete
causation, the presence of every condition but that one which, in
Aristotelian phrase, turns potency into act. And it is in contradistinction
to that idea of possibility that the idea of necessary connection comes in.
When all the elements of the causal antecedent are combined the effect
necessarily supervenes. Furthermore, the causal antecedent is thought of as
necessary in contrast with the contingency of other antecedents whose
connection with the effect is merely accidental. Finally, {84} the idea of
production has been quoted as vitally distinguishing true causation from
invariable sequence. But various myths, of which the story of Oedipus is
the best known, show that primitive folk regard day and night as
alternately producing one another, just as Polonius quotes their sequence
as a type of logical necessity.
Hume professed himself a Deist, but probably with no more seriousness than
when he, or when Gibbon, called Christianity "our religion." At any rate,
his philosophy destroys every argument for the existence of a Creator
advanced in his own or in the preceding century. Nor need his particular
theory of causation be invoked for the purpose. The most telling attack is
on the argument from design. The apparent adaptation of means to ends in
living organisms is quoted as evidence of their having been planned by a
conscious intelligence. But, answers Hume, such an intelligence would
itself exhibit marks of design, and so on for ever. Why not, then, stop at
the animal organism as an ultimate fact? It was Shelley's unlucky demand
for a solution of this difficulty that led to his expulsion from Oxford.
It has been shown how the new analysis of mind cut the ground from under
Berkeley's theism, and from under the metaphysical argument for human
immortality. By denying the substantiality of the ego it also confirmed the
necessitarianism of Spinoza. Hume seemed to think he could abate the
unpopularity of this doctrine by interpreting the constant motivation of
human actions as a mere relation of antecedence and consequence. But the
decisive point was that he assimilated sequences in conscious behaviour to
the unconscious sequences in physical events. Thus, for {85} the vulgar and
the theologians, he remained what would now be called a materialist.
KANT.
The English philosophy of experience and the Continental philosophy of _a
priori_ spiritualism, after their brief convergence in the metaphysics of
Berkeley, parted company once more, the empirical tradition being
henceforth represented, not only by Hume, but in a more or less
anti-Christian and much more superficial form by Voltaire, Rousseau, and
the French Encyclopaedists; while the Leibnizian philosophy was
systematised and taught in Germany by Wolf, and a dull but useful sort of
modernised Aristotelianism was set up under the name of "common sense" by
Thomas Reid (1710-1796) and his school in the Scottish Universities.
The extraordinary genius who was to re-combine the parted currents in a
speculative movement of unexampled volume, velocity, and depth showed
nothing of the precocity that had distinguished Berkeley and Hume. Immanuel
Kant (1724-1804), the son of a saddler of Scottish extraction, was born at
Koenigsberg in Prussia, where he spent his whole life, holding a chair at
the University from 1770 to 1797. It is related that on the day of his
death a small bright cloud was seen sailing alone across the clear blue
sky, of such a remarkable appearance that a crowd assembled on the bridge
to watch it. One of them, a common soldier, exclaimed, "That is Kant's soul
going to heaven!"--a touching and beautiful tribute to the illustrious
German, whose lofty, pure, and luminous spirit it was uniquely fitted to
characterise.
{86}
[Illustration: KANT.
(_Copyright B. P. C._)
{87} Kant grew up among the Pietists, a school which played much the same
part in Germany that the Methodists and the Evangelicals played in England;
indeed, it was from them that John Wesley received his final inspiration.
The Koenigsberg student came in time to discard their theology while
retaining the stern Puritan morality with which it was wedded, and even,
Rationalist as he became, some of their mystical religiosity. What drew him
away to philosophy seems to have been first the study of classical
philology and then physical science, especially as presented to him in
Newton's works. And so the young man's first ambition, after settling down
as a University teacher at Koenigsberg, was to extend the Newtonian method
still further by explaining, on mechanical principles, the origin and
constitution of that celestial system whose movements Newton had reduced to
law, but whose beginning he had left unaccounted for except by--what was
not science--the direct fiat of omnipotence.
Kant offered a brilliant solution of the problem in his _Natural History of
the Heavens_ (1755), a work embodying the celebrated nebular hypothesis
rediscovered forty years later by Laplace. It has been well observed that
great philosophers are mostly, if not always, what at Oxford and Cambridge
would be called "double-firsts"--that is, apart from their philosophy, they
have done first-class work in some special line of investigation, as
Descartes by creating analytical geometry, Spinoza by applying Biblical
criticisms to theology, Leibniz by discovering the differential calculus,
Locke by his theory of constitutional government, Berkeley by his theory of
vision, Hume by his contributions to history and political economy. Kant's
cosmogony may have been premature and mistaken in its details; but his idea
of the heavenly bodies as having originated from the condensation of
diffused gaseous matter still holds its {88} ground; and although the more
general idea of natural evolution as opposed to supernatural creation is
not modern but Greek, to have revived and reapplied it on so great a scale
is a service of extraordinary merit.
The next great event in Kant's intellectual career is his rejection of
Continental apriorism in metaphysics for the empiricism of the English
school, especially as regards the idea of causation. For a few years
(1762-1765) Kant accepts Hume's theory that there is nothing in any
succession of events or in change generally to prove on grounds of pure
reason that there must be more in it than a customary sequence. To believe
that anything may happen without a cause does not involve a logical
contradiction; and at that time he believed nothing to be known _a priori_
except that the denial of which involves such a contradiction. But on
reconsidering the basis of mathematical truth it seemed to him to be
something other than the logical laws of Identity and Contradiction. When
we say that seven and five are twelve we put something into the predicate
that was not affirmed in the subject, and also when we say that a straight
line is the shortest distance between two points. Yet the second
proposition is as certain as the first, and both are certain in the highest
degree, more certain than anything learned from experience, and needing no
experience to confirm them.
So much being admitted, we have to recognise a fundamental division of
judgments into two classes, analytic and synthetic. Judgments in which the
predicate adds nothing to the subject are analytic. When we affirm all
matter to be extended, that is an instance of the former, for here we are
only making more explicit what was already contained in the notion of
matter. On the other hand, when we affirm that all matter is heavy, that is
an {89} instance of the latter or synthetic class, for we can think of
matter without thinking that it has weight. Furthermore, this is not only a
synthetic judgment, but it is a synthetic judgment _a posteriori_; for the
law of universal gravitation is known only by experience. But there are
also synthetic judgments _a priori_; for, as we have just seen, the
fundamental truths of arithmetic and geometry belong to this class, as do
also by consequence all the propositions logically deduced from these--that
is to say, the whole of mathematical science.
Up to this point Kant would have carried the whole Cartesian school, and,
more generally, all the modern Platonists, along with him; while he would
have given the English empiricists and their French disciples a rather hard
nut to crack. For they would have had to choose between admitting that
mathematics was a mass of identical propositions or explaining, in the face
of Hume's criticism, what claims to absolute certainty its truths, any more
than the Law of Causation, possess. Now, the great philosophical genius of
Kant is shown by nothing more than by this, that he did not stop here.
Recognising to the same extent as Locke and Hume that all knowledge comes
from experience--at any rate, in the sense of not coming by supernatural
communication, as Malebranche and Berkeley thought--he puts the famous
question, How are synthetic judgments _a priori_ possible? Or, as it might
be paradoxically expressed, How come we to know with the most certainty the
things that we have not been taught by experience? The answer is, that we
know them by the most intimate experience of all--the underlying
consciousness that we have made them what they are. Our minds are no mere
passive recipients, in which a mass of sensations, poured in from some
external {90} source, are then arranged after an order equally originated
from without; there is a principle of spontaneity in our own subjectivity
by which the objective order of nature is created. What Kant calls the
Matter of knowledge is given from without, the Form from within. And this
process begins with the imposition of the two great fundamental Forms,
Space and Time, on the raw material of sensation by our minds.
By space and time Kant does not mean the abstract ideas of coexistence and
succession; nor does he call them, as some critics used incorrectly to
suppose, forms of thought, but forms of intuition. We do not build them up
with the help of muscular or other feelings, but are conscious of them in a
way not admitting of any further analysis. The parts of space, no doubt,
are coexistent, but they are also connected and continuous; more than this,
positions in space do not admit of mutual substitution; the right hand and
left hand glove are perfectly symmetrical, but the one cannot be
superimposed on the other. Besides, all particular spaces are contained in
universal space, not as particular conceptions are contained in a general
conception, but as parts of that which extends to infinity, and where each
has an individual place of its own, repeating all the characters of space
in general except its illimitable extension. And the same is true of time,
with this further distinction from abstract succession, that succession may
be reversed; whereas the order of past, present, and future is irreversibly
maintained.
The contemporary school of Reid in Scotland, and the subsequent Eclectic
school of Victor Cousin in France, would agree with Kant in maintaining
that sensuous experience will not account for our knowledge of space and
time. But they would protest, in the name {91} of common sense, against the
reduction of these apparently fundamental elements to purely subjective
forms. They would ask, with the German critic Trendelenburg, Why cannot
space and time be known intuitively and yet really exist? Kant furnishes no
direct answer to the question, but he has suggested one in another
connection. Mathematical truth is concerned with spatial and temporal
relations, and for that truth to be above suspicion and exception we must
assume that the objects with which it deals are wholly within our
grasp--that our knowledge of them is exhaustive. But there could be no such
assurance on the supposition that, besides the space and time of our
sensuous experience, another space and time existed independently of our
consciousness as attributes of things in themselves--possibly differing in
important respects from ours--as, for example, a finite, or a
non-continuous, or a four-dimensional space, and a time with a circular
instead of a progressive movement.
This easy assumption that reality accommodates itself to our intellectual
convenience, instead of our being obliged to accommodate our theories of
knowledge to reality, runs through and vitiates the whole of Kant's
philosophy. But, taking the narrower ground of logical consistency, one
hardly sees how his principles can hold together. We are told that the
subjectivity of space and time is not presented as a plausible hypothesis,
but as a certain and indubitable truth, for in no other way can
mathematical certainty be explained. The claim is questionable, but let it
be granted. Immediately a fresh difficulty starts up. What is the source of
our certainty that space and time are subjective forms of intuition? If the
answer is, because that assumption guarantees the certainty of mathematics,
then Kant is {92} reasoning in a circle. If he appeals--as in consistency
he ought--to another order of subjectivity as the sanction of his first
transcendental argument, such reasoning involves the regress to infinity.
Again, on Kant's theory, time is the form of intuition for the inner sense.
So when we become conscious of mental events we know them only as
phenomena; we remain ignorant of what mind is in itself. But before the
publication in 1770 of Kant's inaugural dissertation on _The Sensible and
the Intelligible World_ every one, plain men and philosophers alike,
believed that the consciousness of our successive thoughts and feelings was
the very type of reality itself; and they held this belief with a higher
degree of assurance than that given to the axioms of geometry. By what
right, then, are we asked to give up the greater for the less, to surrender
our self-assurance as a ransom for Euclid's _Elements_ or even for Newton's
_Principia_?
Once more, surely mathematics is concerned not with space and time as such,
but with their artificial delimitations as points, lines, figures, numbers,
moments, etc. And it may be granted that these are purely subjective in the
sense of being imposed by our imagination (with the aid of sensible signs)
on the external world. What if _this_ subjectivity were the true source of
that peculiar certainty belonging to synthetic judgments _a priori_? True,
Kant counts in our judgments about the infinity and eternity of space and
time with other accepted characteristics of theirs as intuitive
certainties. But there are thinkers who find the negation of such
properties not inconceivable, so that they cannot be adduced as evidence of
a priority, still less of subjectivity.
Eleven years after the inaugural dissertation Kant {93} published his most
important contribution to philosophy, _The Critique of Pure Reason_ (1781).
Pure Reason means the faculty by which ideas are obtained independently of
all experience, and the critic's object is to ascertain how far such ideas
are valid. As a preliminary to that inquiry the question is also mooted,
How is experience possible? It is answered by a critique of the
understanding or faculty of conception; and as conception implies
perception, this again is prefaced by a section in which Kant's theory of
space and time is repeated and reinforced.
It will be remembered that what started the whole of the new criticism was
Hume's sceptical analysis of Causation; and the central interest of _The
Critique of Pure Reason_ lies in the effort to reconstitute the causal law
in the light of the new theory of knowledge; but so enormous is the mass of
technicalities piled up for this purpose as largely to conceal it from
view, and, on its disclosure, to give the idea of a gigantic machine set in
motion to crack a nut. And the nut after all is _not_ cracked; the shell
slips from between the grappling surfaces long before they meet.
We have seen how Kant interpreted every judgment as a synthesis of subject
and predicate. Now, whether the synthesis be _a priori_ or _a posteriori_,
a study of the forms of judgment as enumerated in the common logic shows
that there are four, and only four, ways in which it can be effected. All
judgments fall under the following classes: Quantity, Quality, Relation,
and Modality--terms whose meaning will be presently explained. And each of
these again is tripartite. We may say (i.) that one A is B, or that some
A's are B, or that all A's are B; (ii.) that A is B, that A is not B, that
not all A's are B; (iii.) that A is B, that A {94} is B if C is D, that A
is either B, C, or D; or (iv.) that A may be B, that A is B, or that A must
be B. The reason why there are four and only four classes is that judgment
has to do with the subject in reference to the predicate, which gives
Quantity; with the predicate in reference to the subject, which gives
Quality; with the connection between the two, which gives Relation; and
with the synthesis between them in reference to our knowledge of it, which
gives Modality.
Now, according to Kant, that there should be so many kinds of judgment and
no more implies that our understanding contributes a formal element to the
constitution of all knowledge, consisting of four combining principles,
without which experience would be impossible. He calls these Categories,
and they are enumerated in the following table:--
(i.) Quantity.
Unity, Plurality, Totality.
(ii.) Quality.
Reality, Negation, Limitation.
(iii.) Relation.
Substance and Accident; Cause and Effect; Action and Reaction
(Reciprocity).
(iv.) Modality.
Possibility and Impossibility; Existence and Non-Existence; Necessity
and Contingency.
A study of the Categories suggests some rather obvious criticisms on the
Critical Philosophy itself. (i.) The first two terms in each triad
evidently form an antithetical couple, of which the third term is the
synthesis. Here we have the first germ of a disease by which the systems of
Kant's successors were much more seriously infected. In the table it is
shown by {95} the intrusion of Limitation, a wholly superfluous adjunct to
Reality and Negation; in the conversion of Reciprocity into a wholly
fictitious synthesis of Substantiality with Causation; and in the complete
absurdity of making Necessity a combination of Possibility with Existence.
(ii.) Innate ideas, after they had been exploded by Locke, are reintroduced
into philosophy by a sufficiently transparent piece of legerdemain. For
assuming that the human intelligence possesses a power of organising and
drilling the sensuous appearances which without its control would appear
only as a disorderly mob, it by no means follows that they must thereby be
referred to an extraphenomenal principle. But such a principle is plainly
implied by the category of Substance. Used in a scholastic sense, it does
not mean the sensuous attributes of a thing taken altogether, but something
that underlies and supports them. And Kant himself seems to take his
category in that significance. For he claims to deduce from it the law of
the indestructibility of matter; as if I could not say snow is white
without committing myself to the assertion that the ultimate particles of
snow have existed and will exist for ever. (iii.) The substitution of
Causation for logical sequence, as implicated in the hypothetical judgment
of Relation, is perfectly scandalous; and still more scandalous is
substitution of Reciprocity or Action and Reaction for Disjunction. The
last points require to be examined a little more in detail.
The sequence of an effect to its cause has only a verbal resemblance to the
sequence of a logical consequent to its reason. We declare categorically
that every change has a cause which precedes it. Logical sequence is, on
the other hand, as the very name of the {96} judgment shows, hypothetical,
and may possibly not represent any actual occurrence, besides being, what
causation is not, independent of time. A particular case of causation may
be hypothetical in respect to our belief that it actually occurred; never
the law of causation itself as a general truth. And the same distinction
applies with even greater force to the alleged connection between a logical
disjunction and a physical reaction. When I say A is either B or C, but not
both, there is only this much resemblance, that both cases involve the
ideas of equality and of opposition. From the admission that A is not B, I
infer that it is C, or, contrariwise, from the admission that it is B, I
infer that it is not C, and in both instances with the same certainty; but
this does not prove that the earth attracts the moon as much as the moon
attracts the earth, only in opposite directions; nor yet that in certain
instances all the heat lost by one body is gained by another.
Kant had learned this much from Hume, that causation is essentially a
relation of antecedence and consequence in time; and apparently his way of
"categorising" the relation--_i.e._, of proving its apriority--is to
represent it as the logical form of reason and consequent masquerading, so
to speak, under the intuitional time-form. Yet he frequently speaks of our
senses as being affected by things in themselves, implying that the
resulting sensations are somehow caused by those otherwise unknown
entities. But since things in themselves do not, according to Kant, exist
in space and time, they cannot be causally related to phenomena or to
anything else.
In his criticism of Pure Reason, properly so called--that is, of inferences
made by human faculty with {97} regard to questions transcending all
experience--Kant shows that of such things nothing can be known. The
ideality of time and space once taken as proved, this amount of agnosticism
seems to follow as a matter of course. It is idle to speculate about the
possible extent or duration of a universe that cannot be described in terms
of coexistence and succession. For each of us at the dissolution of our
bodily organism time itself, and therefore existence as alone we conceive
it, comes to an end. The law of causation, applying as it does to phenomena
alone, offers no evidence for the existence of a God who transcends
phenomena. Kant, however, is not satisfied with such a simple and summary
procedure as this. He tries to show, with most unnecessary pedantry, that
the conditional synthesis of the Understanding inevitably leads thought on
to the unconditional synthesis of the Reason only to find itself lost in a
hopeless welter of paralogisms and self-contradictions.
At this stage we are handed over to the guidance of what Kant calls the
Practical Reason. This faculty gives a synthesis for conduct, as Pure
Reason gave a synthesis for intelligence. All reason demands uniformity,
order, law; only what in theory is recognised as true has in practice to be
imposed as right. In this way Kant arrives at his formula of absolute
morality: Act so that the principle of thy conduct may be the law for all
rational beings. He calls this the Categorical Imperative, as distinguished
from such hypothetical imperatives as: Act this way if you wish to be happy
either here or hereafter; or, act as public opinion tells you. Moreover,
the motive, as distinguished from the end of moral action, should not be
calculating self-interest nor uncalculating impulse, but simply desire to
fulfil the law as such. Previous moralists had set up {98} the greatest
happiness of the greatest number as the end of action, and such an aim does
not lie far from Kant's philosophy; but they could think of no better
motive for pursuing it than self-love or a rather undefined social
instinct; and their _summum bonum_ would take the happiness of irrational
animals into account, while Kant absolutely subordinates the interests of
these to human good. A further coincidence between the Utilitarian and the
Kantian ethics is that in the latter also the happiness of others, not
their perfection, should be the end and aim of each. Finally, the
philosophy of Pure Reason adopts from contemporary French thought as the
governing idea of political organisation what was long to be a principle of
English Utilitarianism--"the liberty of each, bounded only by the equal
liberty of all."
Nevertheless, the old postulate of a necessary connection between virtue
and individual happiness reappears in Kant's ethical theory, and leads to
the construction of a new religious philosophy. His critique had left no
place for the old theology, nor yet for that doctrine of free-will so dear
to most theologians. Its whole object had been to vindicate against Hume
the necessity and universality of causation. Human actions then must, like
all other phenomena, form an unbroken chain of antecedents and consequents.
Nor does Kant conceal his conviction that, with sufficient knowledge and
powers of calculation, a man's whole future conduct might be foretold.
Nevertheless, under the eighteenth-century idea of man as naturally the
creature of passion or self-interest, he claims for us, as moral agents,
the power of choosing to obey duty in preference to either. And this
freedom is supposed to be made conceivable by the subjectivity of time and
causation, outside of which, {99} as a thing in itself, stands the moral
will. That morality, whether as action or mere intention, involves
succession in time is utterly ignored. Nor is this all. Assuming without
warrant that the moral law demands an ultimate coincidence between
happiness and virtue, made impossible in this life by human weakness, Kant
argues that there must be an unending future life to secure time enough for
working out a problem whose solution is infinitely remote. And, finally,
there must be an omnipotent moral God to provide facilities for undertaking
that somewhat gratuitous Psyche's task. Before Kant moral theology had
argued that the Judge of all the world must do right, apportioning
happiness to desert. It was reserved for him to argue, conversely, that for
right to be done such a Judge must exist, and that therefore he does exist.
In appreciating the services of Kant to philosophy we must guard ourselves
against being influenced by the extravagant panegyrics of his countrymen,
whose passion for square circles he so generously gratifies. Still, after
every deduction for mere Laputian pedantry has been made, the balance of
fruitful suggestion remains vast. (i.) The antithesis of object and
subject, although not counted among the categories of his _Critique_, has
remained a prime category of thought ever since. (ii.) The idea of a
necessary limit to human knowledge, given by the very theory of that
knowledge, as distinguished from the Scepticism of the Greeks--in other
words, what we now call Agnosticism--may not be final, but it still remains
to be dealt with. (iii.) The possibility of reducing _a priori_ knowledge
to a form of unconscious experience has put an end to dogmatic metaphysics.
(iv.) The problems of Time and Space have taken a central place in
speculation; it has been {100} shown--what Hume did not see--that Causation
has the certainty of a mathematical axiom; and it has been made highly
probable that all these difficulties may find their solution in a larger
interpretation of experience. (v.) Morality has been definitely dissociated
from the appeal to selfish interests, whether in this life or in another.
We have now to trace, within the limits prescribed by the nature of this
work, the development of philosophy under Kant's German successors.
* * * * *
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