Читать книгу A Brief History of Modern Philosophy - Harald Høffding - Страница 8

The middle ages developed its theory of nature as well as that of the spiritual life on the foundation of Greek antiquity—except where its ideas were derived from the Bible and Christian tradition.—They received their theory of medicine from Galen, their astronomy from Ptolemy, their philosophy from Aristotle. Their world view was a combination of the theories of Aristotle and Ptolemy with the Biblical doctrines: the earth is stationary and forms the center of the universe; the sun, moon, planets and the fixed stars, attached to firm but transparent spheres, revolve around it. The sub-lunar world, i.e. the earth and the space intervening between the earth and the moon, is the realm of change and death. Here the four elements (Earth, Water, Air, Fire) are in a state of constant motion. Each seeks its “natural place.” Weight consists of the natural tendency to descend, lightness consists of the tendency to ascend. Beyond this moon-sphere is the realm of ether, consisting of matter which has no “natural place,” which is therefore capable of continuing its motion eternally with absolute regularity. The motions of the heavenly bodies—due to this absolute regularity—are a direct copy of the nature ​of Deity. They move in circles because the circle is the most perfect figure; it invariably returns into itself! The universe is bounded by the sphere of the fixed stars which is moved by the Deity himself, whilst the lower spheres are moved by various ethereal spirits.

This world theory seemed to be in harmony with the authorities of the age, Aristotle and the Bible, and at the same time to be in accord with the direct evidence of sense perception. This is why it required such a severe struggle to supplant it. It not only required the repudiation of venerable authorities, but even the most familiar sensory impressions. It was this profound revolution that constituted the stupendous task of the great Copernicus. The epistemological foundations of the ancient world view were unsettled by two men who had no acquaintance with its doctrine.

1. Nicholas Cusanus (1401-1464), a profound thinker with Neoplatonic and mystical tendencies, had even in the fifteenth century gone beyond the traditional view of a limited and stationary universe. Born in Cues (near Trier), he was educated by the “Brothers of the Common Life.” He afterwards continued his studies in Italy. He attained to high ecclesiastical positions and his philosophy has its starting point in theological speculations. In his doctrine of the Trinity he regards the Spirit as the uniting principle which combines the oppositions implied in the characters of Father and Son; spiritus sanctus est nexus infinitus. He afterwards discovers analogous principles in human knowledge and in nature generally.—Falckenberg’s Grundzüge der Philosophie des Nicholas Cusanus (Breslau, 1880) and M. Jacobi’s Das Weltegebaude des Kardinals Nicholas von Cues (1904) are splendid memoirs of this remarkable man. ​All knowledge consists of a process of combination and assimilation. Even sense perception combines various impressions into unitary wholes and these are in turn reduced to ideas and the ideas finally to concepts. In this way the intellect (intelligentia) is forever striving for unity—but it invariably requires an antithesis, something “other than” (alteritas) itself to effect its development. Finally, in order to transcend the antitheses, thought undertakes to conceive them as the extremes of a continuous series. In this way maximum and minimum are united by a continuous series of magnitudes. But we are unable to reconcile all antitheses: thought culminates in antitheses, i.e. there always remains an unassimilated increment beyond itself. It is as impossible for our thought to comprehend the Absolute as it is to describe a circle of pure polygons, even though we may constantly approach it more closely. Although we are incapable of conceiving the Absolute, Deity, we nevertheless understand (such is the nature of the intellect) our incapacity, and the ignorance in which our thought culminates, as a matter of fact, is a scientific ignorance (docta ignorantia). (One of the most interesting of the works of Cusanus is entitled De docta ignorantia.)

This fundamental peculiarity of our knowledge is likewise of importance in the study of nature. We are constantly striving to form continuous series from given points, but without being able to arrive anywhere. Thus, e.g. we can divide our idea of matter to infinity, in experience we must always be satisfied with a finite division, and the atom concept therefore always remains relative. It is the same with the idea of motion: an everlasting, perpetual motion were only possible in case there were no resistance. Here Cusanus anticipates the principle of ​inertia. And the same thing applies even to the determinations of locality: we always regard the objects of the universe from a given place which is, for the time being, the center of the universe for us; the universe as such, however, can have neither center nor circumference, and all motion is relative. The theory that the earth is at the center of the universe is therefore false. However if it is not at the center of the universe, it cannot be at rest; it must be in motion even though we do not perceive it. There is no ground therefore for the assumption that the processes of origin and decay should be confined to the sublunar sphere; we must rather assume that all world bodies are subject to similar conditions to those of the earth. According to Cusanus, therefore, the same principle which precludes our knowledge of Deity likewise demonstrates that the world can neither be limited nor stationary as was hitherto believed.

2. It was characteristic of the ancient, aesthetic conception of nature to emphasize the opposition of Form and Matter. The “Forms” of natural phenomena likewise contained their explanation. Bernardino Telesius (1508-1588) introduces the concept of Force (principium agens) instead of Form (in his work De rerum natura, 1565-1587), as the opposite of Matter. He believes that this conforms more closely with the facts of experience. The “Forms” were mere qualities, which explain nothing. He rejected the traditional theory of the “natural places” and the qualitative distinction of the elements. There are as a matter of fact but two fundamental forces; the one expands (heat), the other contracts (cold), and the various “Forms” which Matter, in itself unchanging and quantitatively constant, assumes must find their explanation by reference to the interaction of these two ​forces. There are no “natural places,” for space is everywhere the same. Different places in space do not of themselves involve any qualitative differences.

Telesius was born at Cosenza in the vicinity of Naples. His circumstances were sufficiently comfortable to provide him the opportunity to devote himself to science. He taught in the University of Naples and founded an Academy in his native city. He had planned to substitute a new theory, based on experience, for Aristotelian Scholasticism. But his critical equipment was inadequate to the accomplishment of this ideal. His general principles however mark an important advance. The details of his natural philosophy are no longer of interest. But his ideas on the psychology of knowledge still continue to be of considerable importance. He tries to bring thought and sensation into the closest possible relation. Should an object which has once been perceived in the totality of its parts and attributes recur at some later time with certain of its parts and attributes lacking, we can supply the parts which are lacking and imagine the object as a totality notwithstanding the fact that we perceive it but in part. We can imagine fire, e.g. with all its attributes, even though we only see its light, without perceiving its heat and its consuming energy. Intellection (intellegere) is the process of construing our fragmentary experience into such a totality. Even the highest and most perfect knowledge simply consists of the ability to discover the unknown attributes and conditions of phenomena by means of their similarity to other cases known as a totality. Inference simply means the recognition of the absent attributes by this method. The simplest sensory impressions are therefore related through a large number of intervening degrees to the highest ​product of scientific thought, and there is no ground for attempting to deduce our knowledge from two different sources or faculties. The problem as to whether similarity is a sensory quality like color and tone remains unsolved, as even Patrizzi, a contemporary of Telesius, charged against him.

Telesius is inclined to ascribe sensitivity to all matter, just as, on the other hand, he regards the soul as material (with this exception, he postulated a supernatural part in the soul on theological grounds which he regarded as a forma superaddita). Every human soul, like everything else, possesses a native impulse towards self-preservation, which constitutes the foundation of ethics. Human virtues represent the various attributes which are favorable to the preservation of the individual. Wisdom is an indispensable condition which must therefore cooperate with all the other virtues (as virtus universalis). The social virtues, which are comprehended under the concept humanitas, are of great importance, because intimate association with others is a necessary condition of self-preservation. The climax of all virtue however is magnanimity (sublimitas), which finds its sufficient satisfaction in its own personal integrity and diligence. Telesius conceived his ethics in the spirit of the Renaissance, and it produced a lasting impression. His natural philosophy and his psychology were likewise very influential, especially over Bacon and Bruno.

3. Nicholas Copernicus (Coppernick), the founder of the modern theory of the universe, was born at Thorn (1473), studied at Cracow and at various Italian Universities and was prebendary at Frauenburg, partly as Administrator, devoting part of his time to his studies. He took no part in the great controversies agitating his ​age. But he seems to have had a measure of sympathy with the religious movement, and he fell into discredit during his latter years on account of his liberal, humanistic tendency. He began the elaboration of his astronomical theory already in 1506, but he was hesitant about its publication, and the first printed copy of his work De revolutionibus orbium coelestium only appeared shortly before his death (1543). The matter which specially concerns us is the epistemological presuppositions which form the basis of this work. Two of its presuppositions must claim our attention.

Nature always takes the simplest course. The theory of the whole universe revolving around so small a body as the earth is inconsistent with this principle. And the case is similar with the theory that the planetary orbits should not be simple circles but a very complicated system of epicycles. On the other hand, if we regard the sun as the center of the universe, and the earth and the planets as revolving around it, we have a very simple theory of the universe.

The second presupposition is the principle of the relativity of motion previously suggested by Cusanus. The perception of motion is not adequately explained by the mere reference to the fact that a perceived object has really changed its position in space. It may likewise be due to the fact that the perceiving subject has moved. If we therefore assume that the earth, from which we observe the motion of the heavenly bodies, is itself in motion (around its axis and around the sun), we will be in position to explain the phenomenon quite as well (only more simply) as the traditional theory.

Copernicus still adhered to the idea of a finite universe and regarded the firmament of the fixed stars, the ​boundary of the universe, as motionless. He believed the planets to be enclosed in a series of concentric permanent spheres. But notwithstanding this he prepared the way for a radical change in the theory of the universe. Facts which apparently rested on the direct evidence of sense perception and were supported by the most famous authorities must now be regarded as discredited! We must awaken to the fact that the system of things which constitutes the universe admits of a different interpretation from the apparent demands of sense perception.

4. Giordano Bruno (1548-1600) is at once the most profound and the most courageous thinker of the renaissance period. Strongly influenced by the philosophy of antiquity and accepting the theories discovered by Cusanus and Telesius, he found a real foundation for his theory of the universe in the new astronomy, as elaborated by Copernicus and later by Tycho Brahe.

Born at Nola in southern Italy, Bruno entered the Dominican order in his early youth. He was soon charged with heresy. His active mind and restive spirit could not endure the rigid monastic discipline. He fled the cloister, discarded the monastic garb and began a wandering career of study and travel, which took him to Switzerland, France, England and Germany. He appears in the capacity of teacher in Toulouse, Paris, Oxford and Wittenburg; but nowhere did he find a permanent position. This was due in part to the opposition of the traditional schools, and in part to his restless disposition. But despite his wanderings he found time to write his ingenious works, among which the Italian dialogues, published in London 1584, deserve special mention. He never regarded reconciliation with the Catholic church ​as impossible, and even cherished the hope of returning to Italy and, without re-entering the cloister, continuing his literary activities. He felt that his career north of the Alps was a failure and Protestantism, with its many little popes, was more reprehensible to him than the ancient church with its single Pope. He finally returned therefore, but was arrested by the Inquisition at Venice (1592) and, after a long imprisonment, burnt as a heretic at Rome in 1600. He died like a hero.

Bruno held Copernicus in high esteem because of his lofty mind. It was he who had lifted him above the illusory testimony of the senses to which the vast majority remained enchained. But notwithstanding his unstinted admiration for the man, he nevertheless regarded the Copernican theory as inadequate because of its conception of the universe as bounded by the sphere of the fixed stars. The basis of Bruno’s opposition to this theory was two-fold, its failure to accord with his theory of knowledge together with his religio-philosophical views.

a. The sensory evidence of an absolute world-center and an absolute world-boundary is merely apparent. The moment we change our viewpoint we attain a new center and a new boundary. Every point in the universe can therefore be regarded at once as both central and peripheral. Abstract thought and sentiency agree in this; namely, that we may add number to number, idea to idea, ad infinitum, without ever approaching an absolute boundary. The possibilities of progress in knowledge are therefore unlimited, and it is from this characteristic of knowledge (la conditione del modo nostro de intendere) that Bruno conceives the character of the universe: absolute boundaries are as inconceivable of the universe as of knowledge. ​It follows therefore that there are no absolute positions. Every position is determined by its relation to other positions. One and the same point may be either center, pole, zenith or nadir—depending entirely on the point from which it is observed (respectu diversorum). There can therefore be no absolute motion and no absolute time. The ancients based their theory of absolute time on the absolute regularity of the motions of the fixed stars; but since the motions observed from any particular star differ from that of another star there are as many times as there are stars. And, finally, the traditional theory of absolute heaviness and lightness is likewise an error; its tenability was based on the presupposition of an absolute center of the universe. Heaviness and lightness must therefore be understood with reference to the various world-bodies. Sun particles are heavy in relation to the sun, earth particles in relation to the earth. According to Bruno, heaviness is the expression of a natural impulse within the parts to return to the greater whole to which they belong.

The principle of relativity is closely connected with the theory that nature is everywhere essentially the same. We can infer the conditions in other parts of the universe from the conditions about us here on the earth. We observe e.g. that ships, when seen at a distance, appear to be motionless, whilst as a matter of fact they are moving very rapidly, and thus by analogy we may assume that the fixed stars appear to be motionless by reason of their great distance from us. There is no justification for maintaining the fixity of the firmament dogmatically as the ancients and even Copernicus had done.

Bruno therefore challenged the dogmatic principles which Copernicus had still accepted. He saw very clearly ​however that the matter cannot be definitely determined by mere speculative generalizations; genuine proof can only come from the discovery of new facts of experience. And he believes furthermore, and rightly so, that no one can investigate the matter without prejudice who adheres dogmatically to the traditional hypothesis.—At one important point he was able to appeal to well-defined facts. He rejected the theory, still accepted by Copernicus, that the stars are enclosed in permanent spheres: If the earth can move freely in space, why should it be impossible for the stars to do the same? And he found his conclusion verified by Tycho Brahe’s investigation of comets, which as a matter of fact pass diagonally through the “Spheres” whose crystal masses were supposed to separate the various parts of the universe! It follows therefore that the contrast of heaven and earth, of permanent and changeable parts of the universe, is untenable.

b. In his philosophy of religion Bruno starts with the infinitude of the Deity. But if the cause or principle of the universe is infinite it must follow that the universe itself is likewise infinite! We are unable to believe that the divine fullness could find expression in a finite universe; nothing short of an infinite number of creatures and worlds would be an adequate display of such fullness.

Bruno elaborated his theory of the infinity of the universe in two dialogues, the Cena de la ceneri and Del’ infinito universo e mondi (1584), and in the Latin didactic poem De immenso (1591). These works are of epochal importance in the history of the human mind. Just as this wide expanse inspired in Bruno a feeling akin to deliverance from the confines of a narrow cell, so the human mind is now presented with a boundless ​prospect forever promising new experiences and new problems.

c. Bruno elaborated his general philosophical principles, which were naturally closely related to the new world theory, in the dialogue De la causa, principio e uno (1584).

Inasmuch as the new world theory annulled the opposition between heaven and earth, Bruno undertakes the task of annulling all oppositions by means of a profounder speculation. Sharp antitheses originate in the human mind and there is no ground for ascribing them to nature. Plato and Aristotle e.g. had no warrant in objective fact for assuming a distinction between Form and Matter. There is no absolute Matter, just as there is no absolute position and no absolute time. Absolute Matter must necessarily be absolutely passive, in which case it could acquire form and development only through some external agency. But in the natural world Forms are not introduced into Matter from without, after the manner of a human artist; they originate from within by an evolution of nature’s own inherent energy. Matter is no less divine than Form and it persists in constant change even as the ancient Atomists had observed. Nature reveals a constant cycle from inorganic matter through the organic processes and back again to the inorganic. According to Bruno’s own statement, he was so profoundly impressed with this idea for a while that he was inclined to regard Forms and the spiritual factor in the universe as unessential and ephemeral. Later on however he perceived that Form and Spirit, no less than Matter, must have their ground in the infinite Principle. He admitted that everything must contain a spiritual principle, at least potentially (secondo la sostanza), even ​if not always actually (secondo l’atto). The ultimate source of all things consists of a Being which transcends the antitheses of Matter and Form, potentiality and reality, body and mind. In so far as this ultimate source is conceived as something distinct from the universe it is called “Cause,” in so far as it is conceived as actively present in natural phenomena it is called “Principle.” The Deity is not a far distant being; it reveals its presence in the impulse towards self-preservation and it is more intimately related to us than we are to ourselves. It is the soul of our soul, just as it is the soul of nature in general, which accounts for the all-pervasive interaction throughout universal space.

The culmination of thought likewise marks its limit, because we are incapable of thinking without antitheses. Every conceptual definition imposes certain limitations; the infinite Principle is therefore incapable of definition. Theology must forever remain a negative science, i.e. a science which eliminates the limitations and antitheses from the concept of Deity. The only significance which positive theology can have, i.e. a theology which undertakes to express the infinite Principle by definite predicates, is practical, didactic and pedagogic. It must address itself to those who are incapable of rising to a theoretical contemplation of the universe. God is indeed more highly honored by silence than by speech.

d. The ideas described above are characteristic of the most important period of Bruno’s philosophical development. It is possible however (with Felice Tocco, in his valuable treatise Opera latine de G. Bruno, 1889) to distinguish an earlier and a later period in his development. During the first period Bruno’s philosophy had somewhat of a Platonic character, in that he regarded general ideas ​as the highest object of knowledge and the universe as an emanation from Deity (De umbris idearum, 1582). But his ideas apparently mean something different from the universal concepts (as in Plato). He seems rather to regard them as laws which describe an actual relationship (e.g. between the different parts of the body).—The last period, as is evident from the De triplici minimo (1591), is noteworthy for its emphasis on the individual elements of being between which this actual relationship obtains. Sensory objects consist of parts notwithstanding the apparent continuity perceived through sense perception. Bruno calls the ultimate, irreducible (or first) parts atoms, minima or monads. There are various classes of monads, and he even calls the universe and God monads, when speaking of them as units.

The distinctions between Bruno’s three points of view—the theory of Ideas, the theory of Substance, and the theory of Monads—however are simply matters of degree.

e. Bruno’s ethics conforms with his general theory of the universe. His Spaccio de la bestia trionfanta (1584) evaluates human virtues according to a new standard. Its dominant characteristic is the prominence given to the desire for truth and to honest toil. Every correct evaluation presupposes truth, and toil is the natural consequence of the task imposed upon man, not merely to follow nature, but to bring forth a new, higher order of nature, that he may become lord of the earth. In the Degli eroici furori (1585) Bruno describes the heroic man as one who is aware that the highest good can only be realized through strife and suffering, but who never despairs, because pain and danger are evils only from the viewpoint of the world of sense, not from the viewpoint of eternity (ne l’occhio del eternitade). The possibilities ​of pain increase with the height of the aim. But the heroic man finds his joy in the fact that a noble fire has been kindled in his breast—even though the goal should be impossible of realization and his soul should be consumed by its profound yearning. This courageous wisdom typifies Bruno’s character as it appears in his life and in his heroic death at the stake.