The Philosophers of the Natural Science Period.
1. Galileo, 1564–1641, and the group of scientists.
2. Bacon, 1561–1626.
3. Hobbes, 1588–1679.
4. The Rationalists.
Countries other than Italy and Germany come upon the philosophic stage during the eighty-nine years of the period of teeming natural science. England is represented by Bacon and Hobbes, France by Descartes, Holland by the Jew, Spinoza, and, at the end of the period, Germany by Leibnitz. Still Italy yields the most influential thinker of them all,—Galileo, who is the most prominent of a long series of astronomers coming from many countries. The most completely representative is Descartes, who was the founder of the Rationalistic school; for he was not only interested in mathematics itself, but in the application of mathematics to metaphysical questions. Neither as influential as Galileo, nor as comprehensive as Descartes, the Englishmen, Bacon and Hobbes, were nevertheless important as the forerunners of the English empirical school. Spinoza is more of a “world’s philosopher” than any of the others, and he joins in his doctrine the scholasticism of the Middle Ages and the mathematics of the Renaissance; while Leibnitz occupies the position between the Enlightenment and the Renaissance.
The Mathematical Astronomers. After enthusiastically canvassing the traditional theories of antiquity, the Humanists had been unable to find one which would explain and organize the newly accumulated materials of their “new world.” But working in more or less narrow circles, natural science had already made a beginning in the midst of the Humanists. Beginning with Copernicus, an interest in physics and astronomy had been aroused, but in these early days it was more speculative than empirical. The speculations of the astronomers had but little influence upon their own time. However, when the ancient theories proved inadequate to explain the facts of the “new world,” and especially when the empirical researches of Galileo confirmed the speculations of his predecessors, the Renaissance turned away from antiquity to nature herself for an explanation. This was about the year 1600, the year of the beginning of the Natural Science period.
The most prominent of these astronomers were—
|Copernicus,||1473–1543, a Pole.|
|Bruno,||1548–1600, an Italian.|
|Tycho Brahe,||1546–1601, a Dane.|
|Kepler,||1571–1630, a German.|
|Galileo,||1564–1641, an Italian.|
|Huyghens,||1629–1695, a Hollander.|
|Newton,||1642–1722, an Englishman.|
While the greatest of these scientists is Newton, who belongs to the next period, the most influential is Galileo. Modern methods in science began with Galileo. Of the four predecessors of Galileo three—Copernicus, Tycho Brahe, and Bruno—are in spirit Humanists; for their final explanation of nature is the world of spirits. Kepler belongs to both the Humanistic and Natural Science periods; for at first he constructed his natural science by an amalgamation of the doctrine of spirits and the Copernican theory; but in the latter part of his life he adopted completely the mechanical view of nature. The above scientists may be divided for convenience into two groups: (1) the speculative scientists before Galileo; (2) Galileo and the following empirical investigators.
For fourteen centuries the ancient Ptolemaic astronomy had been regarded by the learned as beyond question. Although complex and unwieldy, it explained all phenomena satisfactorily enough as they appeared to the senses; and it brought phenomena into a system. (The Ptolemaic system has been fully described in vol. i, pp. 322 ff.) To recapitulate it: the world-all was conceived as a hollow sphere with the earth as the centre and the fixed stars in the periphery, while the planets were supposed to move in epicycles. The universe was divided into the heavenly and terrestrial realms, which were occupied by various spirits. God resided outside this hollow sphere and held it, as it were, in his lap.
The history of the changes leading up to our modern astronomical conception makes a vivid chapter. How Copernicus contributed the idea of placing the sun at the centre of things, Kepler the idea of the orbits of the planets as ellipses, Bruno the idea of the boundlessness of space and time, and how Galileo, corroborating these theories by empirical investigations, was put under the ban of the church—all this shows what heroism must have been required to tear down a time-honored and firmly intrenched traditional conception. Probably the speculative astronomers were not conscious that they were undermining the whole astronomical structure, and probably their sole motive was to simplify the Ptolemaic conception, not to destroy it. For Copernicus accepted the Ptolemaic system, except that he put the sun instead of the earth at the centre, and thereby simplified it by making many of the epicycles unnecessary; and Kepler simplified it further by supplanting the epicycles with ellipses. However, the result was inevitably an entirely new conception of the universe, and with it a new conception of the relation among particular material things. It was in this way that new scientific methods arose.
The universe now comes to be regarded as a mechanism, and what was formerly looked upon as the influence of spirits or as Providential guidance becomes an impersonal law of causal necessity. In the heavens above and the earth beneath there are no longer vital forces and supernatural influences. The universe becomes a homogeneous whole throughout, in which there is no difference between the fall of an apple and the revolution of the planets, no distinction between terrestrial and celestial spheres. The Christian heaven is nowhere in it; the Mediæval spirits are banished from it. The Greek gods have been pushed out, and the Christian God has been made to stand aside.
The demand that the new conception of the universe be verified in concrete experiments, if it were to replace the old Ptolemaic system, the revival of the study of Archimedes, the rivalry in trade and inventions among the Italian towns, were three causes for the demand for greater exactness. Investigation, experiment, and invention came into vogue. Magic, alchemy, astrology, and conjurations were no longer accepted as serious methods. In the Middle Ages deduction had been purely the logical employment of the syllogism in theological discussions, while induction, so far as it was used at all, had been the reference of nature phenomena to spiritual forces. Now deduction and induction6 come to be used for other purposes, and mathematics is necessarily conjoined with both. The new Natural Science period is essentially a “strife of methods”; it is the period when the true plan of scientific procedure is being determined. It is here that the importance and influence of Galileo is seen upon modern science and philosophy.
The influence of mathematics in modern times grew up from these astronomical beginnings among the Humanists; and the Natural Science period with its contention as to methods was the immediate result. Bacon, for example, regarded final causes as one of the “idols.” Hobbes maintained that physics has only to do with efficient causes; Descartes held that it is audacious in man to think of reading the purposes of God in nature; while Spinoza thought it absurd to attribute divine purpose to nature. By degrees everything in nature came to be regarded as a mechanism, and there was no distinction between the animate and the inanimate. The discovery of the mechanical circulation of the blood by Harvey, in 1626, became a vigorous impulse toward the mechanical study of animal life. Descartes regarded animals as complex automata and on this line he published essays on dioptrics, musical law, and the fœtus. Hobbes applied mechanical law to psychological phenomena. The study of reflex action was carried on with great vigor in the Low Countries and France. The mechanical theory was rendered complete in this early time by the exclusion of the soul from the explanation of the body of man, just as God had been pushed into the background of the universe.
Galileo Galilei (1564–1641).7 The dates of the life of Galileo show him to have been a younger contemporary of Bruno, and, like Bruno, to have been a victim of the ecclesiastical reaction that was sweeping away all scientific freedom in Italy. But while Bruno belonged both chronologically and in spirit to the first period of the Renaissance, Galileo is the true beginner of the second period. Bruno was a philosopher of nature, while Galileo was a true scientist. Galileo gave to all future thought a wisely formulated method of dealing with the new materials of the nature world. His laws of projectiles, falling bodies, and the pendulum created a new theory of motion. He set the hypothesis of Copernicus upon an experimental basis and made the future work of Newton possible. He was professor at the Universities of Padua and Pisa, and he was mathematician and philosopher at the court of Tuscany. That he perjured himself and thereby saved his life from the Inquisition, there is no doubt; but instead of death he had an old age of great bitterness. He gave open adherence to the Copernican system in 1610, when he constructed a telescope and discovered the satellites of Jupiter; and after this there followed discovery after discovery, like the spots on the sun and the phases of Venus, which latter discovery confirmed the Copernican hypothesis. He invented the hydrostatic balance, the proportional compass, the thermoscope, microscope, and telescope. His two most noteworthy writings are The Dialogue concerning the Two Most Important World-Systems, and Investigations into Two New Sciences.
As to method, Galileo objected to formal logic, that it is not a means of discovering new truth, although valuable as a corrective of thought. New truth is discovered when we frame an hypothesis from certain experiences, and then infer the truth of other cases from that hypothesis. The hypothesis is first formed by induction from a few characteristic cases; the inference to other cases is made by deduction. He therefore linked induction and deduction closely together, and conceived them as necessarily complementary in scientific investigation. Either induction or deduction alone is absurd and impossible. By induction alone we should be obliged to examine all cases, an impossible undertaking. By deduction alone we should be in the same straits as the Scholastics, and never discover new laws. We must begin with our perceptual experiences and make an induction from them; then we must bring mathematics into use in constructing the hypothesis from which to deduce (calculate) new cases. This is the true, modern method and reveals the great genius of Galileo.
A mathematical law never exactly coincides with any particular concrete relations. A mathematical law is an hypothesis or ideal construction. What value, then, has a mathematical law for science? The orbits of planets8 are described as ellipses, but no actual planet moves in a perfect ellipse. The ellipse is an hypothetical, mathematical orbit for a planet which has no disturbing influences upon it. We get at such a law by the method of concomitant variations;9 and the value of it consists in the simplification and system that it gives the facts. For example, knowing that a planet would move in an ellipse if it suffered no perturbations, and then knowing the influences upon any particular planet, we can calculate its orbit. Mathematical law, although ideal, is the common rule under which all nature phenomena can be brought. However, only by measurements founded on the tests of observation and experiment can we know how far the claims of such deduction are supported. Measure everything measurable, and calculate the measurement of those things not directly measurable.
Nature, therefore, must be called upon to explain her own phenomena. Since the laws of nature are found by investigating nature phenomena as we experience them, the laws must be a part of nature and can be found nowhere else. To explain nature phenomena by referring them to spiritual influence is no real explanation. To say that God moves the planets is to involve the subject in mystery. Here is where Galileo shows that he does not belong to the Scholastics or the Mystics or the Humanists. He searched for some constant element, and not for a “vital force” behind nature phenomena. He declared this constant element to be motion—measurable motion. He is the author of the theory that mechanics is the mathematical theory of motion. Science was therefore taken by him out of the paralyzing grip of the theologian.
The Life of Francis Bacon, Baron Verulam (1561–1626). Francis Bacon was a native of London and received his university education at Cambridge. He was in the English diplomatic service at an early age, but he later returned to London and took up the legal profession. At the age of thirty-two he entered Parliament and became immediately distinguished as a debater. At forty-three he became legal adviser of the crown, and when he was fifty-six he was made Lord Chancellor. After a brilliant career in public office he was accused and convicted of bribery and corruption, deposed from office, and heavily fined. His most notable writings are his Essays, two parts of his uncompleted Instauratio Magna, viz., De Dignitate et Augmentis Scientiarum and Novum Organum, and his New Atlantis, a Utopian fragment.
The Position of Bacon in Philosophy. Tradition has frequently placed Bacon as the founder of modern philosophy. This estimate is due to a remark by Diderot, which was repeated by many French writers. The estimate, however, rests on a misapprehension of Bacon’s influence. Bacon was more of a Humanist than a technical philosopher, and in his constructive philosophy he seems not only to have had no influence upon his contemporaries, but also to have been uninfluenced by them. He was unconscious of the influence of Kepler and Galileo and their mighty scientific constructions. Bacon’s Novum Organum, which embodies his scientific methods, had no influence upon his own time, nor was it read in the seventeenth century. Its influence was first felt in the eighteenth century. However, all this must be qualified in one respect. Bacon’s New Atlantis did have an immediate influence. The ideal of a college of science, which Bacon presented in his New Atlantis, was not only the cause of the work of Diderot in his Encyclopedia in the eighteenth century, but what is more important, it had effect in his own time. It led to the founding of the Royal Society, thirty-six years after Bacon’s death, and later to the founding of similar academies abroad. While the reader may be confused by the conflicting estimates of Bacon, the words of his own countryman, Sir David Brewster, may be accepted as embodying the truth: “Had Bacon never lived, the student of nature would have found in the works and writings of Galileo not only the principles of inductive philosophy, but also its practical application to the noblest efforts of invention and discovery.” So far from being the founder of modern science, Bacon developed only one side of it, the inductive side, and that without success. He identified deduction with the Aristotelian syllogism, and he was therefore unaware of the importance of the use of mathematics in the method of deduction. He did not seem to have the slightest idea that mathematics was going to be the scientific method; consequently science has gone much further than Bacon dreamed it would go. Bacon’s importance in the Renaissance does not consist in his contribution to the content of philosophy or to his successful formulation of the scientific method.
Wherein then lies the value of Bacon’s work as a philosopher?10 Bacon was the first in England to collect the fruits of the Renaissance and give them a secular character. Taking them out of the hands of the theologian, he, a lawyer, “gave them a legal existence by the most eloquent plea that has ever been made for them.” It was a time when philosophy and science were passing out of the hands of the theologian; and Bacon, feeling that science, including philosophy, should be secularized, drew a sharp line between the work of science and that of theology. Out of his great contempt for antiquity, Bacon voiced for England the contemporary reaction against the old scholastic methods. He set up the ideal and gave directions for following it. He issued the call to go from abstractions back to things. A man of worldly wisdom and pungency, his nature was buoyant in its belief in the coming age. He had confidence amounting to an optimism that final principles would be found to explain all the particulars of the “new world.” He was a prophet who outlined his prophecy. He felt that not only nature but all the activities of man would be reduced to some simple principles. He shared and expressed the confidence of his time that wonderful things were to be revealed; that nothing is impossible to man, provided man hits upon the right key to nature’s secrets. Just as every age, that feels itself upon the threshold of a new epoch, writes Utopias,11 so Bacon wrote the New Atlantis, the Utopian fragment, for his age. This is the literary expression of his optimism about the future of a distinctively secular science. The world of the New Atlantis is the world of new machines. Bacon’s most ambitious scientific contribution to the same end is his Instauratio Magna. Of this only two parts were completed: De Dignitate et Augmentis Scientiarum and Novum Organum. Bacon is best known in philosophy by the second part, which was thus named to contrast it with the “old” Organum of Aristotle.
The high influence that Bacon gained later among philosophers may therefore be accounted for by the association of his eminent position and wonderful personality with his bold expression of this congenial utilitarianism. Even in that rich Elizabethan age of English literature, he was prominent as a writer and politician. He had occupied high political positions under James I; but his peculiar personality would in itself have attracted attention, for his genius was such that any of the products of that age—even the plays of Shakespeare—have seemed possible to him. Pope describes him as “the wisest, brightest, meanest of mankind.” Macaulay says in his essay, Bacon, that there were many things that he loved more than virtue and many that he feared more than guilt. His career shows that he loved himself, wealth, and learning. His unusual love for learning may be safely taken as his excuse for his unscrupulous lust for wealth. His great versatility prevented his success in any one direction, but he had the power of expressing the feeling of his impressive age and of becoming its personal representative.
The Aim of Bacon. Bacon sought to secularize philosophy by making it the same as science. It was the age when Nature was conceived to be identical with the world of the natural sciences. Bacon stood in this age as the formulator of the scientific usefulness of philosophy. Philosophy is to ameliorate social conditions and enrich human life by bringing nature under control. Ancient and mediæval times had not been occupied with the improvement of human society, but Bacon was inspired with the feeling of the modern statesman for such improvement. The true test of philosophy, according to Bacon, is what it will do. That philosophy is worth while which will effectively remove the weighing conditions upon human society, so that there are no longer two classes,—those that sacrifice and those that satisfy their ambitions. This dominant utilitarian motive in Bacon sets him in opposition to pure theoretical and contemplative knowledge, and makes him the father of utilitarianism and positivism12 in England.13 Knowledge is the only kind of permanent power, and man can master the world when he gives up verbal discussions and belief in magic. Man must gain a positive insight into nature. Science and philosophy must be separated from theology, and philosophy must be reduced to science. Thus while aiming to give a tangible form to the scholastic doctrine of the “twofold truth,” Bacon through his utilitarianism missed the goal reached by Galileo and Descartes.
The Method of Bacon. Bacon says that the method of the scientist should not be like that of the spider that spins a web out of himself, nor like that of the ant which merely collects material, but like that of the bee which collects, assimilates, and transforms. Bacon’s original inspiration had been his respect for method, and this grew more pronounced. Philosophy, i. e. science, is method. With Bacon we see the beginning of philosophy cut loose from personality and over-valued because it had mechanical accuracy. Nevertheless, the method of Bacon was very comprehensive. It included on the one hand a critical survey of the past, and on the other an anticipatory programme for the science of the future. Let us now turn to these two aspects of his method.
(a) Bacon’s criticism of the past was a trenchant criticism of prevailing philosophy, and amounted to a break with the past. Bacon felt that what passed for science in his day was but a pretence. In the presence of the facts of life traditional science was but empty words. The early thinkers are not the ancients. We are the ancients, for we embody in ourselves all the preceding centuries. Thus does Bacon swing from the mediæval blind acceptance of the past to an equally blind rejection of the past. But why did the ancient thinkers err? Not because they were not men of talent, nor because they lacked in intellectual opportunity; but because their method of procedure led them astray. The early thinkers followed wrong paths, and their results, which we now possess, are vain.
What must be our attitude in the presence of this traditional philosophy? We must dispossess ourselves of the prejudices that have misled the past, for they form the obstacles to our true knowledge of the world. The roots of the errors that have infected philosophy are “fantastic, contentious, and delicate learning.” We must not, indeed, trust to our every-day perceptions; for although science is based on our perceptions, our every-day perceptions are corrupted by our uncritical habits of thought. Thus there have arisen perversions and falsifications, of which we must first of all be rid. Bacon calls these Idols.14 Idols are false images, that intervene between us and the truth and are mistaken for reality. Bacon makes four general classes of Idols:—
(1) The Idols of the Tribe, or the presuppositions common to the human race.
(2) The Idols of the Cave,15 or individual prejudices due to natural individual disposition, situation in life, etc.
(3) The Idols of the Forum, or the traditional meanings of words, by which we substitute the word for the idea. These are the worst illusions.
(4) The Idols of the Theatre,16 the theories or philosophic dogma, which command discipleship from groups of men and have not been subjected to our own criticism.
Bacon’s classification of our prejudices as Idols is a critical attempt to separate, in what passes for knowledge, the subjective, which has become traditional, from the real. Logic, religion, and poetry have had a bad effect on science, as is especially shown in the theatrical character of philosophy.
(b) Having dispossessed ourselves of our prejudices or Idols, we are ready to proceed to a positive construction of a scientific method of work. By what, in general, ought science to be guided? By induction and experience. Bacon suggests the following steps for the science of the future:—
(1) There must be an exhaustive collection of particular instances.
(2) There must then be an analysis and comparison of these instances, for to Bacon induction was not a mere enumeration of single instances. Negative instances, and instances of difference of degree, must be taken into account. Hasty generalizations must be avoided, and we must ascend gradually from the particular to the general.
(3) The simple “form” of the phenomenon must be discovered. Of the four causes of Aristotle, Bacon emphasizes the “formal.” By “form” Bacon means the nature that is always present when the phenomenon is present, absent when the phenomenon is absent, and increases or decreases with the phenomenon. The “form” is the abiding essence of the phenomenon.
The English Natural Science Movement. The natural science movement in England thus received at the start the impression of the sober Anglo-Saxon mind. Through its entire history English philosophy differed from that of the Continent. Here at the outset the Englishman is skeptical, not only of scholastic deductions from dogma, but also of deductions of all kinds.17 He prefers the slow road of patient empirical discovery. Even pure contemplative knowledge and the deductions of mathematics have little charm for him. To be sure, induction even in the hands of an Englishman demands by its nature the establishment of a general principle, but Bacon would have refused to use such a deduction to establish a new truth in the way that Galileo used his mathematical hypotheses. According to Bacon, an hypothesis is true only so far as it has already received the indispensable sanction of experience.
Thomas Hobbes18 and his Contemporaries. During a certain period Bacon had under him a secretary by the name of Thomas Hobbes. Here was an obscure man turning to philosophy because of his interest in politics; whose point of attachment to philosophy was the mechanical theory of nature, so universally accepted by the scientists of that time. No contemporary of Hobbes—neither Bacon, Descartes, nor Galileo—had so systematic a philosophy. No other man succeeded better in expressing all that was in his mind. Hobbes was one of a large group of political theorists of the Renaissance. When the mediæval idea of the universal Christian state, such as was embodied in Augustine’s City of God, was no longer held, many of the Humanists tried to construct theoretical systems of political government that would meet the demands of the time. Macchiavelli, Thomas More, Bodin, Althusius, and Grotius19 belong to this group. Hobbes is best known in modern times as a writer on this aspect of morals and politics; but politics is only a part of his general mechanical system of the universe. He is the forerunner of modern materialism, and his peculiar theory of society is only an exemplification of this theory.
In passing from Bacon to Hobbes we come to a very different type of man. Bacon had risen to fame by his own genius, in spite of the hostility of his powerful relatives; Hobbes was a hard-headed man, with a narrow outlook, but with undoubted talents, which were fostered all his life under the patronage of the Devonshire family. Bacon was a practical politician; Hobbes was a doctrinaire and theoretical political writer. Of the voluminous literary remains of Bacon his philosophy forms but a small part; Hobbes had a general philosophical system, with which his classical and theological studies have connection.
In the succeeding chapter we shall review the philosophy of the rationalist, Descartes, who was a contemporary of Hobbes. We shall find that Descartes and Hobbes are alike in this: that both employed Galileo’s mathematical theory as authoritative. They differed, however, in the way in which they used Galileo’s theory. Descartes reduced mathematics to the rational, and conceived it to be the instrument of the reason; Hobbes reduced the rational to the mathematical, and conceived the reason as a form of mechanics. The starting-point of Descartes was the subjective, and he was held at a standstill until the relation of thought and mechanics was solved by him. The point of view of Hobbes was objective, and since all was mechanical, he discussed only incidentally the relation between thought and mechanical existence. Hobbes conceived the world in the terms of only one series, the mechanical. Descartes’ main motive was to preserve the rational; and, consequently, the world to him consisted of a double or dualistic series of terms. We therefore place Descartes, with Spinoza and Leibnitz, in a group called Rationalists. Hobbes was a materialist, and his greatness consisted in going the full length of materialism: he went beyond all the scientists of his time by extending the mechanical theory to the mental life.
The Life and Writings of Hobbes (1588–1679). The life of Hobbes falls into five natural periods. In his first and last periods he was the classical scholar. During his middle period of about thirteen years he was the philosopher. Furthermore, at one time he was absorbed in mathematics and at another in controversy. His period as mathematician was begun not until he was forty years old, and was preparatory to his creative philosophical period, which was begun when he was about fifty.
1. As a Classical Scholar (including his early years) (1588–1628)—the first forty years of his life. At Oxford (1603–1608); first journey abroad (1608–1612); beginning of his relations with the Devonshire family and also of his acquaintance with the “new science”; time of leisurely study (1612–1628) and acquaintance with Bacon, Herbert of Cherbury, and Ben Jonson; translation of Thucydides (1628).
2. As Mathematician (1628–1638). Second journey abroad (1629–1631) for eighteen months as tutor to the son of Sir Gervase Clifton; reads Euclid while abroad; third journey abroad (1634–1637), when he meets Galileo; begins to develop the conception of motion and sensation; by 1638 he is counted among the notable philosophers and he meets the Parisian scientists, Mersenne and Gassendi.
3. As Philosopher (1638–1651). Plans his philosophy under title of Elements of Philosophy: De Corpore, De Homine, and De Cive, which is interrupted by the English Revolution; Elements of Law (“little treatise”) written in 1640, read by a few in manuscript, published without his consent in 1650 in two parts: Human Nature and De Corpore Politico; flees to Paris (1640) and enters again the scientific circle at Paris; criticises Descartes’ Meditations; De Cive published (1642), which is De Corpore Politico enlarged; acts for a time as tutor to Charles II in Paris; engages upon his general philosophical theory (1642–1645); Liberty and Necessity, written (1646), published (1654); Leviathan published (1651).
4. As Controversialist (1651–1668). Flees back to London (1651); De Corpore, published (1655); Behemoth, written (1668), proscribed and not published until after his death; controversies with Bramhall, Ward, Wallis, and Boyle; De Homine, published (1658).
5. As Classical Scholar (1668–1679). Translation of Iliad and Odyssey (1675).
In Molesworth’s edition (1839–1845), Hobbes’ Latin works occupy five volumes, the English eleven. The Elements of Philosophy—the De Corpore, De Homine, and De Cive—were not published in the sequence in which they were planned, but, on account of political exigencies, in the above order.
The Influences upon the Thought of Hobbes. 1. The premature birth of Hobbes had no inconsiderable influence upon his life. When his mother was carrying him, she had suffered a great fright, at the announcement of the approach of the Spanish Armada. Was it in consequence of this that Hobbes’s life was a series of panics and controversies? He was extremely conservative in politics. He saw the new changes without sympathy with either party, and he had no political ideals—only fear. The time in which he lived reinforced this natural conservatism. When he was translating Thucydides, Buckingham was assassinated and the Petition of Rights was presented. Henry IV of France had been assassinated not many years before, and the Puritan element had become a disturbing factor in England. His study and his alliance with the Devonshire family confirmed him in his conservative position. All signs of the time pointed toward decentralization of government, toward war and rebellion. In fear he was “the first that fled” to France at the beginning of the troubles of Charles I; in fear he fled back to London eleven years later, lest the Roman Catholics, whom his Leviathan had offended, should murder him. Hobbes was again in great panic over the London fire and looked upon it as a divine penalty, on account of the impurity of the English court. Hobbes was always in fright lest he might not have peace.
2. The father of Hobbes was one of the unworthy clergymen of the English Established Church in the reign of Elizabeth. He was a dissolute man, and after many escapades he abandoned his family. In consequence of this Hobbes always had an antipathy toward the offices of the church and toward theology. Although he claimed to be a communicant, his allegiance was only nominal, as his theory will show.
3. Hobbes was very much influenced by the new mathematical science. His years at Oxford left little impression upon him, and he was but little interested in the scholasticism which was taught there. Yet his twenty years on the Continent brought him into the midst of the scientific circles of Italy and France. He was well along into maturity when he felt this influence. On his second journey, he read Euclid for the first time. He was then forty-three. On his third journey, he met Galileo and the French scientists, Mersenne and Gassendi, and it was then that he began his reflections concerning motion and sensation. The writings of Kepler, Descartes, and Galileo influenced him mightily. Although he acted as Bacon’s secretary after the latter’s fall, Bacon’s influence upon him was little and has been overestimated. The mental powers of Bacon and his secretary were different, and Bacon knew nothing of the mathematical method. Hobbes shows to some degree the empirical tendency of his nationality, and he believed that knowledge must spring from experience. Further than this, the method that Bacon pursued does not appear in him. The mission of Hobbes was to construct a mechanical view of the world.
Of the three influences upon Hobbes, his inherited timidity is seen in his conservative political theory; the influence of his father is seen in his theory of religion; the influence of the “new” mathematical science is seen in his whole philosophy, especially in his psychology.
The Fundamental Principle in the Teaching of Hobbes. The assumption from which Hobbes deduced his entire philosophy was the mechanical conception of the physical world,—the characteristic philosophical assumption of his age. Hobbes’s contemporaries, both the natural scientists and the philosophers, had, however, on the whole, restricted the conception of mechanism to the physical world. Hobbes differed from them all in universalizing the conception. He extended its application from the physical over upon the mental realm, and thereby reduced the mental world to physics. He stated this mechanical principle in two parts: all that exists is body; all that occurs is motion. Hobbes applies this assumption to the physical world and it gives him materialism;20 he applies it to knowledge and it gives him sensationalism;21 he applies it to the will and it gives him determinism;22 he applies it to morals and politics and it gives him naturalism.23 Body is nature; body is everything. Body is the first term leading through man up to the State. With Hobbes, as with others of his time, the political field was the whole ground to be penetrated. The fundamental principle, by which Hobbes thought the whole field was to be explained, is body in motion. The mental world became drawn into the physical, and thereby his mechanical conception became the more natural.
There was one realm which Hobbes left untouched by his principle: the realm of the spirit, i. e. God, souls, angels. The science of bodies cannot deal with the supernatural, for the supernatural does not consist of bodies in motion. Matter and mind are homogeneous; matter and spirit are not. The contrast in Hobbes is not between matter and mind, the material and the psychical, but between matter and spirit, the material and the supra-material.
The Method of Hobbes. Hobbes made the method of Galileo his own. He believed that all knowledge is rooted in mathematics. There is one true method of treating all subjects: the mathematical calculation of them as motions of bodies. Knowledge consists in using words as the signs of experience and in reckoning with them. Scientific thought is the combination of signs. It is the rationalizing of our experiences. Science has a truth in itself and stands as a rationally organized world, quite different from the world of experience which it has organized. The world of bodies in causally related motions is such an organized world, the most systematized and most simply constructed world that science can devise. But how does the scientist proceed? He begins with a phenomenon, which is a body in motion, and finds out the causes of the phenomenon, which causes are nothing more nor less than the elements of the phenomenon in question. Then the scientist proceeds from the causes to other phenomenal effects. These new effects are like the original phenomenon and its causes,—bodies in motion. Thus the world of the scientist is a world of causes and effects, for “the natural reason of man is busily flying up and down among the creatures, and bringing back a true report of their order, causes, and effects.” Thus we find Hobbes to be a nominalist (see vol. i, p. 358) who, nevertheless, used the deductive method—rather a strange combination. Like all his English successors, he employed induction and deduction, but the two processes never became fused.24 Moreover for induction he has no method.
The order in which the writings of Hobbes appeared seems to have been the sport of outward events, for they were not written according to his original plan. On his return from his third journey to the Continent (1638), Hobbes, then fifty years old, had adopted the mechanical theory and had planned his philosophy. His comprehensive work was to be called the Elements of Philosophy, and was to be divided into three parts: De Corpore, treating physical bodies; De Homine, treating man as a psychological individual; De Cive, treating man as the citizen of a State. Hobbes’s philosophy was therefore to be a universal philosophy, and he intended to bring his works out in logical order—first, the science of physics, then of human nature, and last of society. However, the growing disturbances in the political world at that time moved him to publish several treatises on politics first, and his physics and psychology more than fifteen years later.
The Kinds of Bodies. There are two kinds of bodies, natural and artificial. Natural bodies are those belonging to the physical world. The artificial bodies are the institutions of society, of which the most important is the State. Man belongs to both classes of bodies—he has a physical nature and he is a member of the State. Man is the connecting link between natural and artificial bodies. Philosophy is therefore divided into three parts: physics, which treats of purely natural bodies; psychology, which treats of man in his rôle as a natural individual; politics, which treats of man in social congregations with his fellows. Looking at the situation from the other end, political bodies are decomposable into men, men are in turn decomposable into physical bodies. Political bodies are dependent on the psychical nature of men, and the psychical nature of men is dependent on the nature of physical bodies, i. e. on bodies and their motions. Thus all bodies, natural and artificial, must be explained in terms of motion, if they are explained scientifically. Physical bodies are the first term leading up through man to the last term in the series, which is the State.
Hobbes’s Application of the Mathematical Theory to Psychology. Although the prime interest of Hobbes lay in the political life of man, he nevertheless made an original contribution to psychology. He snatched the science of mental phenomena from the hands of the scholastic theologian and made it for the first time an independent science. Psychology had been based upon the assumptions of the theologian; for these Hobbes substituted the assumptions of the mathematician. Consciousness became in his hands not a soul, but the motion of bodies. It is described by him as “the movement of certain parts of the organic body.” The states of consciousness, such as sensations, perceptions, etc., are brain movements or the refined movements of atoms in the nervous system. Memory and imagination are “decaying sensations”; thought is the sum of several sensations; experience is the totality of sensations bound together by the rigid laws of association. Hobbes was the father of what is known as the Associational Psychology, or the theory that consciousness is composed of mental atoms under fixed laws of association.
But although Hobbes took psychology out of the hands of the theologian and made it a mechanical science, he did not identify it with physics. It is still psychology. The mental states are the physical motion of bodies, but they are not external motions, nor are they the copies of the external motions of bodies. Mental states are brain movements; they are the result of external motions. They come about in this way. A moving body in the outer world makes an impression on the sense organ, and this motion is transmitted by the nerves to the heart and brain. A reaction is effected in the brain, and this is a mental state. The brain transformations, and not the movement of the external object, is that of which we are conscious. The mental state is an “apparition” of the actual fact in the external world; it is an effect in a causal series. Our perception of light is, for example, a modification of the cerebral substance, and not of the external body itself. We deceive ourselves when we think that the sensations of light, sound, heat are outside us. These qualities of things are modifications of ourselves. There is nothing external to us, except the motions of bodies which are the causes of these modifications. The external world is no doubt real, but we have no knowledge of it—no knowledge of aught save the motions of bodies within ourselves. This is the point of view of all subsequent English philosophy: the substance of things is quite different from our knowledge of them. The substance of things is real; but is not the object of our knowledge. The object of our knowledge is a modification of ourselves.
The independence of knowledge with reference to theology on the one side, and to physical reality on the other, is well illustrated in Hobbes’s discussion of language. Speech consists of words, which are only the counters of things. Words are markers by which men may know a thing as “seamen mark a rock.” Science consists in their manipulation. Science combines them by addition and subtraction into judgments and syllogisms, and thereby constructs a body of demonstrated principles. Words are only counters, and he is a fool who mistakes the counter for the coin of reality. Words only represent reality, and the law of their use is mathematics. Truth and falsity are terms that are concerned with the correct or incorrect manipulation of these verbal counters and not with real things.
Hobbes’s Application of the Mathematical Theory to Politics. In the same way that material bodies in motion give rise to mental states, and mental states as bodies in motion give rise to the human consciousness, so men as individuals are the source of the artificial body,—the State. In every individual man the impulse to self-preservation is innate, and is, in fact, his absolute and universal characteristic. Just as the law of the mechanical association of ideas is the fundamental principle of the human mind, so the mechanical law of self-preservation is the principle of man’s ethical and political life. All our political institutions are the result of the striving of men for self-preservation. In his natural state—when, as Hobbes conceived, man lived without social organization—man had no other standard for conduct than his own self-interest; in the artificial political state, which man has constructed, self-interest is still his motive. Egoism is the sole working principle of human beings both before and after they live in societies; but the political state is the most ingenious contrivance which egoism has hit upon for its own profit. Hobbes conceived that the original state of man, which under the name of “state of nature” was a common problem in the Renaissance, was a condition in which every man was making war against every other man. (Compare Locke and Rousseau.) But such a condition of things was obviously self-destructive. Consequently man arbitrarily and artificially formed the political State to avoid this self-destructive, internecine warfare. Under the circumstances it was the most effective way in which man could gain his personal ends, for the political State was the only possible means to peace. In the “state of nature” the right of every man to everything was the equivalent of the right of every man to nothing. So men made a compact with one another under which each relinquished a portion of his rights in order that each might have a portion of them secure. But what gives security to this compact? The sovereign to which the powers of the many have thus been delegated. What is the sovereign? It is the soul of the State, the general will,—represented by a single person in a monarchy, by an assembly in a republic. This sovereign, in whom the contract is vested, is absolute; for the sovereign was not a party to the original contract, since he did not then exist. The contract was made among the individuals, at that time in a “state of nature.” So long as the State preserves its power among the people, the people must render their obedience to the State,—to the sovereign in whom the contract was vested. The might of the political State makes right. Whatever the State commands is right; whatever is forbidden is wrong. There was no right and wrong in the “state of nature,” only the possible and the impossible. An act is a crime when it breaks the contract, and thus the ground of morality is political legislation. Even the religion of the people is determined by the State. Any political State is better than a revolution. Here was philosophical justification of Charles I. A reversion to war is a reversion to the “state of nature.”
When Hobbes was in France as a refugee he wrote the Leviathan, which contained this doctrine of political society. He presented a vellum-bound copy to Charles II, hoping to gain favor with that prince. However, the Leviathan, unfortunately for Hobbes’s purpose, contained two paragraphs that antagonized the royalists and the Catholics. One was, that when a commonwealth is unable to protect its citizens in peace, that commonwealth is dissolved and a new sovereign commonwealth is formed. The second was, that while the sovereign state shall decide what the religion of its people shall be, no religion is infallible—neither Anglican, Catholic, nor Puritan. The religion that the sovereign makes legal is only a temporary one; the true religion will come not until the Last Judgment. The church is subordinate to the State, like everything else, and it does not matter much what the State religion shall be, provided there be peace. Religion is only a superstition resting on a defective knowledge of nature, and it is of little consequence what particular religion the State makes binding.
It hardly need be said that the Leviathan pleased neither Charles II nor the Catholics. The sequel of its publication was that Hobbes fled back to England from fear of assassination.
The Renaissance in England after Hobbes. The philosophies of Bacon and Hobbes do not exhaust, but merely represent the philosophy of England during the Renaissance. Empiricism25 had to wait for Locke in the next period before it became dominant. After Hobbes Scholasticism was narrowly confined to limited circles and appeared under the form of Skepticism or of Platonism, neo-Platonism, or Mysticism. The reaction toward Platonism was centred in a group of ethical scholars, called the Cambridge School. It included Culverwell, Cudworth, Henry More, and Cumberland. This Platonic movement was short-lived. The scientific spirit, represented in the Renaissance by Bacon and Hobbes, dominated the next period,—the Enlightenment,—and we shall find it spreading its influence over France and Germany in the form that Locke gave to it.
But the history of the philosophy of the Renaissance is not yet completed. Contemporary with Bacon and Hobbes, there was a movement on the Continent which was more characteristic of the Renaissance, and indeed more important to it than the movement in England. This was the school of Rationalists, to which we now turn.