rejection of final causes by both Bacon and Descartes. Perhaps the most
effective of their novelties was the effort of Descartes to explain the
system of the world by matter and motion only, thus quietly setting
aside all causes and metaphysical entities which had hitherto been
invoked. The hypothesis of vortices was indeed soon disclosed to be
untenable; but the scientific attitude from which that hypothesis
proceeded was never afterward relinquished. It was a bold attempt at the
application of the objective method, and was only defective in its
restriction to cosmology, and its exclusion of biology, which was still
left to the subjective method, as I shall presently notice.
The second point on which Bacon and Descartes resemble each other is in
their conception of the results to be achieved by a totally new method.
Coming as they did on the top of the revolutionary wave which had washed
away the old methods, seeing as they saw the striking results of
physical research, and foreseeing yet more glorious conquests from the
spirit which achieved those results, they yielded themselves to the
pleasant illusion that a new method would rapidly solve all problems.
Bacon, as the more magnificent and imaginative mind, had grander visions
and more enthusiastic faith; but Descartes also firmly believed that the
new method was to do wonders. Indeed, it is interesting to note how
these great intellects seem quite unconscious of their individual
superiority, and are ready to suppose that their method will equalize
all intellects. It reminds us of Sydney Smith maintaining that any man
might be witty if he tried. Descartes affirms that "it is not so
essential to have a fine understanding as to apply it rightly. Those who
walk slowly make greater progress if they follow the right road than
those who run swiftly on a wrong one." To the same effect Bacon: "A
cripple on the right path will beat a racer on the wrong one." This is
true enough, but is beside the question. Equipped with good or bad
instruments, the superiority of one worker over another is always made
manifest; and it is precisely in the right use of a good method that the
scientific genius is called upon for its delicate and patient skill.
Into the vexed questions of Bacon's conduct, both with regard to Essex
and with regard to bribery, I cannot enter here; but referring the
curious to his biographers and critics, I will simply note that he was
born in 1561; was educated at Trinity College, Cambridge, where he
learned to distrust the Aristotelianism of his masters, and planned his
own vast scheme of reform; went to Paris; sat in Parliament as member
for Middlesex; was successively appointed of the Privy Council, and lord
chancellor; was created Viscount Verulam; was impeached and condemned
for corruption as a judge; and died in the spring of 1626. "For my name
and memory," said the dying man, "I leave it to men's charitable
speeches, and to foreign nations, and the next age."
Posterity has been generous; the fame of Bacon is immense. Admirers have
not always been unanimous as to his special claims; but there has been
no lack of enthusiasm, no questioning of his genius. He has been lauded
for achievements in which he had no part, and has been adorned with
titles to which he had doubtful pretensions; while his most important
services have been overlooked. But the general recognition of his
greatness, and our national pride in it, have not prevented certain
attacks on his reputation, which have been answered in a rather angry
spirit; and thus from one cause and another there is great difficulty in
arriving at any candid and thorough appreciation of the work he did. It
seems to some persons that Bacon did very little in rising against the
philosophy of his day, and pointing out a new path; and to others it
seems that he did nothing of the kind. But whoever looks closely into
the writings of Bacon's predecessors will see that what now seems
obvious and trivial was then startling and important. As M. Rémusat
felicitously says, "_Il fallait du génie pour avoir ce bon sens_." And
to those who deny that Bacon did head the revolution, I would oppose not
simply the testimony of nearly three centuries, but the testimony of
Gassendi, who, both as contemporary and as foreigner, was capable of
judging the effect then produced. It is indeed apparent to anyone
familiar with the writings of some of Bacon's immediate predecessors,
especially Galileo, that there was little novelty in his denunciations
of the erroneous method then popular, or in his exhortations to pursue
observation, experiment, and induction. But it is not less apparent that
he had wider and profounder views of the philosophy of method than any
of them, and that the popular opinion does not err in attributing to him
the glory of heading the new era.
In England he is commonly regarded as the "Father of Experimental
Philosophy" and the originator of the inductive method. Men profess
themselves followers of the "Baconian philosophy," sometimes confounding
that with a servile attention to facts and a most unscientific scorn of
theories; at other times implying that by the Baconian method is to be
understood the one on which science has successfully been pursued. A
rigorous investigation of Bacon's claims will disclose the truth of his
own statement, that he was rather one who sounded the trumpet-call than
one who marshalled the troops. He insisted on the importance of
experiment, but he could not teach what he did not himself
understand--the experimental method. He exhorted men to study nature;
but he could not give available directions for that study. He had
fervent faith in the possible conquests of science; but never having
thoroughly mastered any one science, he was incapable of appreciating
the real conditions of research. He saw clearly enough the great truth
that the progress of research must be gradual, but he did not see what
were the necessary grades, he did not see the kind of inquiries, and the
order they must follow before discoveries could be made.
That he had really but vague and imperfect conceptions of scientific
method is decisively shown by his contemptuous rejection of Copernicus,
Galileo, and Gilbert, and by his own plan of investigation into heat.
One sentence alone would suffice to show this, namely, his sneer at
Copernicus as "a man who thinks nothing of introducing fictions of any
kind into nature, provided his calculations turn out well." Bacon did
not understand, what Copernicus profoundly saw, that the only value of
an hypothesis was its reconciliation of calculations with observations.
In his plan for an inquisition into the nature of heat, we see a total
misconception of the scientific process; not only does he set about in a
laboriously erroneous way, but he seeks that which science proclaims
inaccessible, the nature of heat. It is true that he arrives at a
hypothesis which bears some resemblance to the hypothesis now accepted,
namely, that heat is a mode of motion--"an expansive and restrained
motion, modified in certain ways, and exerted in the smaller particles
of the body." But those who have been eager to credit him with an
anticipation of modern views on the strength of this definition, have
overlooked the fact that it is incapable of explaining a single process,
includes none of the ascertained laws of phenomena, and is itself an
example of the illicit generalization which Bacon elsewhere condemns. It
was with some justification, therefore, that Harvey, who knew what
science was, and knew better than most men how discoveries were made,
said of him that he wrote of science like a lord chancellor.
Indeed, it is to mistake his position and his greatness altogether to
attribute his influence on philosophy, which is undeniable, to an
influence on science which is more than questionable. Bacon was a
philosopher; but because with him philosophy, separating itself from the
bondage of theology, claimed to ally itself with science, and sought its
materials in the generalities of science, those writers who have never
made a very accurate distinction between the two, but have confounded
philosophy with metaphysics, and science with physics, have naturally
regarded Bacon as the precursor of Newton, Laplace, Faraday, and Liebig.
It is in vain that critics oppose such a claim by asserting what is
undeniable, that the great discoveries in modern science were neither
made on Bacon's method nor under any direct guidance from him--that
Copernicus, Galileo, and Kepler preceded him, that Harvey and Newton
ignored him--stanch admirers have their answer ready; they know that
Bacon was the herald of the new era, and they believe that it was his
trumpet-call which animated the troops and led them to victory.
Having thus indicated his position, it will be necessary to give a brief
outline of the method which he confidently believed was to be infallible
and applicable in all inquiries. This was imperatively needed: "for let
a man look carefully into all that variety of books with which the arts
and sciences abound, he will find everywhere endless repetitions of the
same thing, varying in the method of treatment, but not new in
substance, insomuch that the whole stock, numerous as it appears at
first view, proves on examination to be but scanty. What was asserted
once is asserted still, and what was a question once is a question
still, and, instead of being resolved by discussion, is only fixed and
fed."
He proposes his new method, that thereby "the intellect may be raised
and exalted and made capable of overcoming the difficulties and
obscurities of nature. The art which I introduce with this view (which I
call the 'Interpretation of Nature') is a kind of logic, though the
difference between it and the ordinary logic is great, indeed immense.
For the ordinary logic professes to contrive and prepare helps and
guards for the understanding, as mine does; and in this one point they
agree. But mine differs from it in three points: viz., in the end aimed
at, in the order of demonstration, and in the starting-point of inquiry.
"But the greatest change I introduce is in the form itself of induction
and the judgments made thereby. For the induction of which the logicians
speak, which proceeds by simple enumeration, is a puerile thing;
concluded at hazard, is always liable to be upset by a contradictory
instance, takes into account only what is known and ordinary, and leads
to no result. Now, what the sciences stand in need of is a form of
induction which shall analyze experience and take it to pieces, and by a
due process of exclusion and rejection lead to an inevitable
conclusion."
"Now, my method, though hard to practise, is easy to explain; and it is
this: I propose to establish progressive stages of certainty. The
evidence of sense, helped and guarded by a certain process of
correction, I retain; but the mental operation which follows the act of
sense I for the most part reject; and instead of it I open and lay out a
new and certain path for the mind to proceed in, starting directly from
the simple sensuous perception."
The same dissatisfaction with mediæval philosophy expressed itself in
Descartes. The incompetence of philosophers to solve the problems they
occupied themselves with--the anarchy which reigned in the scientific
world, where no two thinkers could agree upon fundamental points--the
extravagance of the conclusions to which some accepted premises led,
determined him to seek no more to slake his thirst at their fountains.
"And that is why, as soon as my age permitted me to quit my preceptors,"
he says, "I entirely gave up the study of letters; and resolving to seek
no other science than that which I could find in myself, or else in the
great book of the world, I employed the remainder of my youth in travel,
in seeing courts and camps, in frequenting people of diverse humors and
conditions, in collecting various experiences, and above all in
endeavoring to draw some profitable reflection from what I saw. For it
seemed to me that I should meet with more truth in the reasonings which
each man makes in his own affairs, and which, if wrong, would be
speedily punished by failure, than in those reasonings which the
philosopher makes in his study, upon speculations which produce no
effect, and which are of no consequence to him, except perhaps that he
will be more vain of them the more remote they are from common-sense,
because he would then have been forced to employ more ingenuity and
subtlety to render them plausible."
For many years he led a roving, unsettled life; now serving in the army,
now making a tour, now studying mathematics in solitude, now conversing
with scientific men. One constant purpose gave unity to those various
pursuits. He was elaborating his answers to the questions which
perplexed him; he was preparing his method.
When only twenty-three he conceived the design of a reformation in
philosophy. He was at that time residing in his winter quarters at
Neuburg, on the Danube. His travels soon afterward commenced, and at the
age of thirty-three he retired into Holland, there in silence and
solitude to arrange his thoughts into a consistent whole. He remained
there eight years; and so completely did he shut himself from the world
that he concealed from his friends the very place of his residence.
When the results of this meditative solitude were given to the world in
the shape of his celebrated _Discourse on Method_, and his
_Meditations_--to which he invented replies--the sensation produced was
immense. It was evident to all men that an original thinker had arisen;
and although this originality could not but rouse much opposition, from
the very fact of being original, yet Descartes gained the day. His name
became European. His controversies were European quarrels. Charles I of
England invited him over, with the promise of a liberal appointment; and
the invitation would probably have been accepted had not the civil war
broken out. He afterward received a flattering invitation from Christina
of Sweden, who had read some of his works with great satisfaction, and
wished to learn from himself the principles of his philosophy.
He accepted it, and arrived in Stockholm in 1649. His reception was most
gratifying, and the Queen was so pleased with him as earnestly to beg
him to remain with her, and give his assistance toward the establishment
of an academy of sciences. But the delicate frame of Descartes was ill
fitted for the severity of the climate, and a cold, caught in one of his
morning visits to Christina, produced inflammation of the lungs, which
carried him off.
Christina wept for him, had him interred in the cemetery for foreigners,
and placed a long eulogium upon his tomb. His remains were subsequently
(1666) carried from Sweden into France, and buried with great ceremony
in Ste. Geneviève du Mont.
Descartes was a great thinker; but having said this, we have almost
exhausted the praise we could bestow upon him as a man. In disposition
he was timid to servility. When promulgating his proofs of the existence
of the Deity, he was in evident alarm lest the Church should see
something objectionable in them. He had also written an astronomical
treatise; but hearing of the fate of Galileo, he refrained from
publishing, and always used some chicane in speaking of the world's
movement. He was not a brave man, nor was he an affectionate man. But he
was even-tempered, placid, and studious not to give offence.
It has already been indicated that the great work performed by Descartes
was, like that of Bacon, the promulgation of a new method. This was
rendered necessary by their separation from the ancient philosophy and
their exclusion of authority. If inquiry is to be independent, if reason
is to walk alone, in what direction must she walk? Having relinquished
the aid of the Church, there were but two courses open: the one to tread
once more in the path of the ancients, and to endeavor by the ancient
methods to attain the truth; or else to open a new path, to invent a new
method. The former was barely possible. The spirit of the age was deeply
imbued with a feeling of opposition against the ancient methods; and
Descartes himself had been painfully perplexed by the universal anarchy
and uncertainty which prevailed. The second course was therefore chosen.
Uncertainty was the disease of the epoch. Scepticism was widespread, and
even the most confident dogmatism could offer no criterion of certitude.
This want of criterion we saw leading, in Greece, to scepticism,
Epicureanism, Stoicism, the New Academy, and finally leading the
Alexandrians into the province of faith, to escape from the dilemma. The
question of a criterion had long been the vital question of philosophy.
Descartes could get no answer to it from the doctors of his day. Unable
to find firm ground on any of the prevalent systems, distracted by
doubts, mistrusting the conclusions of his own understanding,
mistrusting the evidences of his senses, he determined to make a _tabula
rasa_, and reconstruct his knowledge. He resolved to examine the
premises of every conclusion, and to believe nothing but upon the
clearest evidence of reason; evidence so convincing that he could not by
any effort refuse to assent to it.
He has given us the detailed history of his doubts. He has told us how
he found that he could plausibly enough doubt of everything except of
his own existence. He pushed his scepticism to the verge of
self-annihilation. There he stopped; there in self, in his
consciousness, he found at last an irresistible fact, an irreversible
certainty.
Firm ground was discovered. He could doubt the existence of the external
world, and treat it as a phantasm; he could doubt the existence of a
God, and treat the belief as a superstition; but of the existing of his
thinking, doubting mind no sort of doubt was possible. He, the doubter,
existed if nothing else existed. The existence that was revealed in his
own consciousness was the primary fact, the first indubitable certainty.
Hence his famous "_Cogito, ergo sum_" ("I think, therefore I am").
It is somewhat curious, and, as an illustration of the frivolous verbal
disputes of philosophers, not a little instructive, that this celebrated
"_Cogito, ergo sum_," should have been frequently attacked for its
logical imperfection. It has been objected, from Gassendi downward, that
to say, "I think, therefore I am," is a begging of the question; since
existence has to be proved identical with thought. Certainly, if
Descartes had intended to prove his own existence by reasoning, he would
have been guilty of the _petitio principii_ Gassendi attributes to him,
viz., that the major premise, "that which thinks exists," is assumed,
not proved. But he did not intend this. What was his object? He has told
us that it was to find a starting-point from which to reason--to find an
irreversible certainty. And where did he find this? In his own
consciousness. Doubt as I may, I cannot doubt of my own existence,
because my very doubt reveals to me a something which doubts. You may
call this an assumption, if you will: I will point out the fact as one
above and beyond all logic; which logic can neither prove nor disprove;
but which must always remain an irreversible certainty, and as such a
fitting basis of philosophy.
I exist. No doubt can darken such a truth; no sophism can confute this
clear principle. This is a certainty, if there be none other. This is
the basis of all science. It is in vain to ask for a proof of that
which is self-evident and irresistible. I exist. The consciousness of my
existence is to me the assurance of my existence.
Had Descartes done no more than point out this fact he would have no
claim to notice here; and we are surprised to find many writers looking
upon this "_Cogito, ergo sum_" as constituting the great idea in his
system. Surely it is only a statement of universal experience--an
epigrammatic form given to the common-sense view of the matter. Any
clown would have told him that the assurance of his existence was his
consciousness of it; but the clown would not have stated it so well. He
would have said, "I know I exist, because I feel that I exist."
Descartes therefore made no discovery in pointing out this fact as an
irreversible certainty. The part it plays in his system is only that of
a starting-point. It makes consciousness the basis of all truth. There
is none other possible. Interrogate consciousness, and its clear replies
will be science. Here we have a new basis and a new philosophy
introduced. It was indeed but another shape of the old formula, "Know
thyself," so differently interpreted by Thales, Socrates, and the
Alexandrians; but it gave that formula a precise signification, a thing
it had before always wanted. Of little use could it be to tell man to
know himself. How is he to know himself? By looking inward? We all do
that. By examining the nature of his thoughts? That had been done
without success. By examining the process of his thoughts? That, too,
had been accomplished, and the logic of Aristotle was the result.
The formula needed a precise interpretation; and that interpretation
Descartes gave. Consciousness, said he, is the basis of all knowledge;
it is the only ground of absolute certainty. Whatever it distinctly
proclaims must be true. The process, then, is simple: examine your
consciousness, and its clear replies. Hence the vital portion of his
system lies in this axiom: All clear ideas are true: whatever is clearly
and distinctly conceived is true. This axiom he calls the foundation of
all science, the rule and measure of truth.
The next step to be taken was to determine the rules for the proper
detection of these ideas; and these rules he has laid down as follows:
1. Never accept anything as true but what is evidently so; to admit
nothing but what so clearly and distinctly presents itself as true that
there can be no reason to doubt it.
2. To divide every question into as many separate questions as possible;
that each part being more easily conceived, the whole may be more
intelligible--(Analysis).
3. To conduct the examination with order, beginning by that of objects
the most simple, and therefore the easiest to be known, and ascending
little by little up to knowledge of the most complex--(Synthesis).
4. To make such exact calculations and such circumspections as to be
confident that nothing essential has been omitted.
Consciousness, being the ground of all certainty, everything of which
you are clearly and distinctly conscious must be true; everything which
you clearly and distinctively conceive exists, if the idea of it
involves existence.
In the four rules, and in this view of consciousness, we have only half
of Descartes' system; the psychological half. It was owing to the
exclusive consideration of this half that Dugald Stewart was led--in
controverting Condorcet's assertion that Descartes had done more than
either Galileo or Bacon toward experimental philosophy--to say that
Condorcet would have been nearer the truth if he had pointed him out as
the "Father of the Experimental Philosophy of the Mind." Perhaps the
title is just; but Condorcet's praise, though exaggerated, was not
without good foundation.
There is, in truth, another half of Descartes' system, equally
important, or nearly so: we mean the deductive method. His eminence as a
mathematician is universally recognized. He was the first to make the
grand discovery of the application of algebra to geometry; and he made
this at the age of twenty-three. The discovery that geometrical curves
might be expressed by algebraical numbers, though highly important in
the history of mathematics, only interests us here by leading us to
trace his philosophical development. He was deeply engrossed in
mathematics; he saw that mathematics were capable of a still further
simplification and a far more extended application. Struck as he was
with the certitude of mathematical reasoning, he began applying the
principles of mathematical reasoning to the subject of metaphysics. His
great object was, amid the scepticism and anarchy of his contemporaries,
to found a system which should be solid and convincing. He first wished
to find a basis of certitude--a starting-point: this he found in
consciousness. He next wished to find a method of certitude: this he
found in mathematics.