George Henry Lewes, born in London on April 18, 1817, was the
grandson of a famous Covent Garden comedian. As an actor,
philosopher, novelist, critic, dramatist, journalist, man of
science, Lewes played many parts in the life of his time, and some
of them he played very well. George Eliot owed him a great deal; he
turned her genius away from pure speculation, and directed it to
its true province--fiction. Lewes was, in fact, an excellent
critic, and it is by his splendid critical work, the "Biographical
History of Philosophy," that he is now best remembered. In this
remarkable book, which appeared in 1845-46, Lewes the novelist and
the journalist collaborates with Lewes the philosopher and man of
science. He has the rare art of making an abstruse subject clear
and attractive; he does not give a dry summary of the ideas of the
great thinkers, but depicts the living man and relates his way of
life to his way of thinking. The result is that in his hands
metaphysic becomes as interesting as history did in the hands of
Macaulay.
_I.--The Early Thinkers_
It is the object of the present work to show how philosophy became a
positive science; to indicate by what methods the human mind was enabled
to conquer its present modicum of certain knowledge. The boldest and the
grandest speculations came first. Man needed the stimulus of some higher
reward than that of merely tracing the laws of phenomena. Nothing but a
solution of the mystery of the universe could content him. Astronomy was
derived from astrology: chemistry from alchemy, and physiology from
auguries. The position occupied by philosophy in the history of mankind
is that of the great initiative to positive science. It was the forlorn
hope of mankind, and though it perished in its efforts, it did not
perish without having led the way to victory.
Thales, who was born at Miletus, in Asia Minor, and flourished in 585
B.C., is justly considered the father of Greek speculation. The step he
took was small but decisive. He opened the physiological inquiry into
the constitution of the universe. Seeing around him constant
transformations--birth and death, change of shape, of size, and of mode
of being, he could not regard any one of these variable states of
existence as existence itself. He therefore asked, What is the beginning
of things? Finding that all things were nourished by moisture, he
declared that moisture was the principle of everything. He was mistaken,
of course, but he was the first man to furnish a formula from which to
reason deductively.
Anaximenes (550 B.C.) pursued the method of Thales, but he was not
convinced of the truth of his master's doctrine. He thought that the air
was the prime, universal element, from which all things were produced
and into which all things were resolved. Diogenes of Apollonia adopted
the idea of Anaximenes, but gave a deeper significance to it. The older
thinker conceived the vital air as a kind of soul; the younger man
conceived the soul as a kind of air--an invisible force, permeating and
actuating everything. This attribution of intelligence to the primal
power or matter was certainly a progress in speculation; but another
line of thought was struck out by Anaximander of Miletus, who had been a
friend of Thales. He was passionately addicted to mathematics, and a
great many inventions are ascribed to him; among others, the sun-dial
and the geographical map.
In his view, any one single thing could not be all things, and in his
famous saying, "The infinite is the origin of all things," he introduced
into metaphysics an abstract conception in place of the inadequate
concrete principles of Thales and his disciples. Pythagoras was a
contemporary of Anaximander, and, like him, one of the great founders of
mathematics. He held that the only permanent reality in the cosmos was
the principle of order and harmony, which prevented the universe from
becoming a blank, unintelligible chaos; and he expressed this idea in
his mystic doctrine: "Numbers are the cause of the material existence of
things." The movement which he spread by means of a vast, secret
confraternity ended, however, in a barren symbolism, and it is
impossible to trace what relation his strange theories of the
transmigration of souls and the music of the spheres have to his general
system of thought.
Far more influence on the progress of speculation was exercised by
Xenophanes of Colophon. Driven by the Persian invasion of 546 B.C. to
earn his living as a wandering minstrel, he developed the ideas of
Anaximander, and founded the school of great philosophic poets, to which
Parmenides, Empedocles and Lucretius belong. He is the grand monotheist,
and he has published his doctrines in his verses:
There is one God alone, the greatest of spirits and mortals,
Neither in body to mankind resembling, neither in ideas.
Shelley's line: "The One remains, the Many change and pass," sums up the
teaching of the line of thinkers which culminated in Plato. In their
view, knowledge derived from the senses was fallacious because it
touched only the diverse and changing appearances of things; absolute
knowledge of the one abiding spiritual reality could, they held, only be
obtained by the exercise of spiritual faculty of reason, which, unlike
the animal power of sense, is the same in all men. One of the
philosophers of this school, Zeno of Elea, was the inventor of the
dialectic method of logic, which Socrates and Plato used with so
tremendous an effect.
Anaxagoras, however, attempted to reconcile the evidence of the sense
with the dictates of the reason. He was the first philosopher to settle
in Athens, and Pericles, Euripides, and Socrates were among his pupils.
He was extraordinarily modern in many of his ideas. He held that the
matter of knowledge was derived through the senses, but that reason
regulated and verified it, and he carried this dualism into his
conception of the universe, which he represented as a manifestation of a
Divine intelligence, acting through invariable laws, but in no way
confused with the matter acted on.
His successor, Democritus, adopted his theory of the origin of
knowledge, and by applying it to the problem of the One and the Many,
produced the most striking of ancient anticipations of modern science.
He regarded the world as something made up of invisible particles, each
absolutely similar to the other; these formed the essential unity which
could be grasped only by the reason, but by their various combinations
and arrangements they brought about the apparent multiplicity of objects
which the senses perceived. Such was the foundation of the atomic theory
of Democritus. He conceived the atom as a centre of force, and not as a
particle having weight and material qualities. As, however, his
hypothesis was purely a metaphysical one, it did not lead to any of the
discoveries which have followed on the establishment of the modern
scientific theory, which was arrived at in a different way, and has a
different signification. Democritus also threw out in vague outline the
idea of gravitation. But this was not science: it was guess-work; it
afforded no ground on which the fabric of verified knowledge could be
erected, and no sure method of obtaining this knowledge.
_II.--The School of Socrates_
It was against the vain and premature hypotheses of the physiologists of
his day that the greatest and noblest intellect in Greece revolted.
Socrates was the knight-errant of philosophy.
It was his confessed aim and purpose to withdraw the mind from the
contemplation of the phenomena of nature, and fix it on its own
phenomena. "I have not leisure for physical speculations," he said, with
characteristic irony, "and I will tell you why: I am not yet able,
according to the Delphic inscription, to _know myself_, and it seems to
me very ridiculous, while ignorant of myself, to inquire into what I am
not concerned in." Weary of disputes about the origin of the universe,
he turned to the one field in which the current method of abstract
reasoning could be fruitfully applied--the field of ethics.
Living in an age of wild sophistry, he endeavoured to steady and
enlighten the conscience of men by establishing right principles of
conduct. His method of proceeding by definitions and analogy has been
misapplied, but in his hands it was a powerful instrument in discovering
and marking out a new field of inquiry. His religious genius, the ideal
character of his ethics, and the heroic character of his life, have been
his great titles to fame, but it is his method which gives him his high
position in the history of philosophy.
The method of Socrates was adopted and enlarged by the most famous of
all ancient writers. Aristocles, surnamed Plato (the broad-browed), was
a brilliant young Athenian aristocrat who turned from poetry to
philosophy on meeting, in his twentieth year, with Socrates. After
travelling abroad in search of knowledge, he returned to Athens and
founded his world-renowned Academy there in 387 B.C. With vast learning
and puissant method, he created an influence which is not yet extinct
Plato was the culminating point of Greek philosophy.
In his works all the various and conflicting tendencies of preceding
eras were collected under one method. This method was doubtless the
method of Socrates, but much extended and improved. Socrates relied on
definitions and analogical reasoning as the principles of investigation.
Plato used these arts, but he added to them the more scientific
processes of analysis, generalisation, and classification.
In regard to his system of thought, Plato was a realist. He believed
that ideas have a real existence, and that material things are only
copies of the realities existing in the ideal world. He held that
beauty, goodness, and wisdom are spiritual realities, from which all
things beautiful, good, and wise derive their existence.
In his philosophy the universe is divided into the celestial region of
ideas and the mundane region of material phenomena, answering to the
modern conception of heaven and earth. As the phenomena of matter are
but copies of ideas (not, as some suppose, the bodily realisation of
them), there arises a question: How do ideas become matter? Plato gives
two different explanations. In the "Republic" he says that God, instead
of perpetually creating individual things, created a distinct type
(idea) for each thing, and from this type all objects of the class are
made. But in a later work, the "Timaeus," Plato takes another view of the
origin of the world. Types are conceived as having existed from all
eternity, and God, in fashioning cosmos out of chaos, fashioned it after
the model of these eternal types.
Plato's conception of heaven and earth as two distinct regions is
completed by his conception of the double nature of the soul; or,
rather, of two souls, one rational and the other sensitive. The
sensitive soul awakens the divine reminiscences of the rational soul;
and the rational soul, by detecting the One in the Many, preserves man
from the scepticism inevitably resulting from mere sense-knowledge.
Aristotle, who was born in 384 B.C., was Plato's pupil. He, however,
completely broke away from his master's theory. He maintained that
individual objects alone exist. But if only individual objects exist,
only by the senses can they be known; and if we have only
sense-knowledge, how can we arrive at the general truths on which both
philosophy and science are founded? This was the problem which had led
Plato to claim for ideas, or types of general truths, a higher origin
than the intermittent and varying data of the senses.
Aristotle held that it could be solved in a natural way without the
conception of an ideal world. In his view, ideas were obtained by
induction. Sensation is the basis of all knowledge. But we have another
faculty besides that of sensation; we have memory. Having perceived many
objects, we remember our perceptions, and this enables us to discern
wherein things differ and wherein they agree. Then, by means of the art
of induction, we arrive at ideas. Aristotle's theory of induction is
clearly explained by him: "Experience furnishes the principles of every
science. Thus astronomy is grounded on observation. For if we were to
observe properly the phenomena of the heavens, we might demonstrate the
laws which regulate them. The same applies to other sciences." Had he
always held before his eyes this conception of science, he would have
anticipated Bacon--he would have been the Father of Positive Science.
But he could not confine himself to experience, as there was not
sufficient experience accumulated in his age from which to generalise
with any effect. So he turned to logic as an instrument for
investigating the mystery of existence, and by bringing physics and
metaphysics together again, he paved the way for a new era--the era of
scepticism.
All the wisdom of the ancient world was powerless against the sceptics.
Faith in truth was extinct; faith in human nature was gone; philosophy
was impossible. And, though the influence of Socrates continued to be
felt in the field of ethics, the ethics of the Greeks were at best
narrow and egotistical. What a light was poured upon all questions of
morality by that one divine axiom, "Love your enemy." No Greek ever
attained the sublimity of such a point of view. Still, the progress made
by the Greeks was immense, and they must ever occupy in the history of
humanity an honourable place.
_III.--Philosophy and Science_
Francis Bacon is the father of experimental philosophy. He owes his
title to his method. Many philosophers, ancient and modern, had
cursorily referred to observation and experiment as furnishing the
materials of physical knowledge; but no one before him had attempted to
systematise the true method of discovery.
He begins his great work by examining into the permanent causes of
error, as these were likely to be operative even after the reformation
of science. For this reason he calls them idols, or false appearances
(from the Greek, _eidolon_), and he divides them into four classes: the
idols of the tribe, or the causes of error due to the general defects of
the human mind; the idols of the den, which spring from weaknesses
peculiar to the character of the individual student; the idols of the
forum, which arise out of the intercourse of society and the power that
words sometimes have of governing thought; and, finally, the idols of
the theatre, which men of great learning pursue when they follow the
systems of famous but mistaken thinkers.
After this preliminary discussion, Bacon goes on to describe the methods
of inductive science. The first step consists in preparing a history of
the phenomena to be explained in all their modifications and varieties.
This history must include not merely such facts as spontaneously offer
themselves, but all experiments instituted for the sake of discovery. It
must be composed with great care; the facts should be accurately related
and distinctly arranged, and their authenticity diligently examined;
those that rest on doubtful evidence should not be rejected, but noted
as uncertain, with the grounds of the judgment so formed. This last part
of the method, says Bacon, is very necessary, for facts often appear
incredible only because we are ill-informed, and they cease to seem
marvellous when our knowledge is further extended.
When this record of facts, this "natural history," is completed, an
attempt may then be made to discover, by a comparison of the various
facts, the cause of the phenomena. Here it is of the utmost importance
to bear in mind that all facts have not the same value. There are, as
Bacon points out, twenty-seven species of facts, and he concludes that
in any science where facts cannot be tested by experiment there can be
no conclusive evidence.
Thus it will be seen that Bacon's method was a system of specific rules.
He did not merely tell men to make observations and experiments; he
taught them how observations and experiments ought to be made.
As Bacon was the father of modern science, so Rene Descartes was the
father of modern philosophy. Born in 1596, and perplexed by the movement
of scepticism produced by the Renaissance, the French thinker
endeavoured to find some ground of certainty in the fact that he at
least knew of his own existence. Hence his famous saying: _Cogito, ergo
sum_--"I think, therefore I exist." Consciousness, said he, is the basis
of all knowledge. The process then is simple: examine your
consciousness, and its clear replies will be science. Hence the vital
portion of his system lies in this axiom: "All clear ideas are true."
The fallacy in his system can be briefly exposed. Consciousness is, no
doubt, the ultimate ground of certainty of existence for _me_. But
though I am conscious of all that passes within myself, I am not
conscious of what passes in anything not myself. All that I can possibly
know of anything not myself lies in its effects upon me. Any other ideas
I may have in regard to the outside world are founded only on
inferences, and directly I leave the ground of consciousness for the
region of inference my knowledge becomes questionable.
It was this defect in Cartesianism which Baruch Spinoza, the great
Jewish thinker of Amsterdam, set out to rectify. Spinoza asked himself:
What was the reality which lies beneath all appearance? We see
everywhere transformations perishable and perishing, yet there must be
something beneath which is imperishable and immutable. What is it? In
Spinoza's view, the absolute existence is God. All that exists, exists
in and by God. Taking the words of St. Paul, "In Him we live and move
and have our being," as his motto, he undertook to trace the relations
of the world to God and to man, and those of man to society.
To John Locke, born at Wrington, in Somerset, in 1632, the problem
presented itself in another way. Instead of accepting the validity of
clear ideas, as Descartes and Spinoza did, he adopted the Baconian
method, and opened the inquiry into the origin and formation of ideas.
Separating himself from the philosophers who held that the mind was
capable of arriving at knowledge independent of experience, and from the
sceptics who maintained that the senses were the only channels of
information, he showed that ideas were derived from two
sources--sensation and reflection.
He was succeeded by George Berkeley, Bishop of Cloyne, born at Kilcrin
in Kilkenny, in 1684. He defeated the sceptics on their own ground.
There is nothing in the world, he says, except our own sensations and
ideas. In order to exist for us, things have to be perceived by the
mind; therefore, everything, in order to exist, must exist in the mind
of God. But when Berkeley had proved that matter was figment, David
Hume, born in 1711, came forward and showed that mind was also an
illusion. You know nothing of matter, said Berkeley; you have only
perceptions and the ideas based thereon. You know nothing of mind,
replied Hume; you have only a succession of sensations and ideas.
Against Hume rose up in Germany a famous school of philosophers
beginning with Immanuel Kant, who was born in Prussia in 1724. Kant
attempted to prove that the human reason was not untrustworthy, as Hume
assumed, but limited, and that, within certain bounds, it was capable
of arriving at practical truths. Kant's disciples, however, were not
content with this modest restatement. Taking it too readily for granted
that Hume's objections had been overcome, they proceeded to revive that
unbounded faith in mere speculation which had been the distemper of the
Greek mind. Fichte and Schelling were the first thinkers of note to
attempt again to solve by logic the mystery of the universe.
But their works are now obscured by the achievement of Hegel, who began
to teach at Berlin in 1818. Hegel holds that the real universe is a
universe of ideas to which his philosophy is the key, but, as ideas
realise themselves in space and time, they come within the scope of the
man of science. It is said that all bad German systems of philosophy
when they die come to England. Hegelianism has certainly been very
fashionable in this country, and its influence is still observable in
academic circles.
Auguste Comte is the Bacon of the nineteenth century. It has been his
object to construct a _positive_ philosophy; that is to say, a doctrine
capable of embracing all the sciences, and, with them, all the problems
of social life. He holds that every branch of knowledge passes through
three stages: the supernatural, or fictitious; the metaphysical or
abstract; the positive or scientific. When the positive method is
adopted, then shall we again have one general doctrine, powerful because
general.
The metaphysicians have failed to penetrate to the causes of things, but
the men of science are succeeding in the humbler but far more useful
work of tracing some of the laws that govern the phenomena of nature,
and foreseeing their operations. It is only where the philosophers
started matters capable of _positive_ treatment that any advance has
been made in metaphysics. For the rest, philosophy leaves us in the
nineteenth century at precisely the same point at which we were in the
fifth. Thus is the circle completed.