CHAPTER LI
THE SCIENTIFIC MOVEMENT

The forerunner of the great scientific movement of the sixteenth century was Nikolaus of Cusa (1401-1464). Nikolaus was born at Kues, or Cusa, near Treves, in 1401. At an early age he joined the community of the Brothers of the Common Life at Deventer. Later he studied law, mathematics, and philosophy at Padua, but finally decided to abandon the legal profession and took holy orders. In 1448 he was made cardinal, and two years later was appointed to the see of Brixen. He died at Todi in Umbria in 1464. His most important works are the treatise De Docta Ignorantia and the dialogue entitled Idiotae de Sapientia Libri Tres. These were published at Paris in 1514 and at Basel in 1565.

In his speculative philosophy Nikolaus occupies a position intermediate between Aristotelian and modern thought: he insists with special emphasis on the doctrine of the unity of opposites (coincidentia oppositorum) and on the principle that the beginning of true wisdom is the knowledge of one's own ignorance (Docta Ignorantia). Among his astronomical teachings is that of the rotation of the earth on its axis, -- a doctrine to which Copernicus subsequently gave scientific form.

Nicholas Copernicus (1473-1543) was born at Thorn in Poland in 1473. After studying at Cracow, Bologna, and Padua, he became canon of Frauenburg. In a treatise De Orbium Celestium Revolutionibus, which appeared in 1543 and was dedicated to Pope Paul III, he defended the heliocentric system of astronomy and definitely placed the earth among the solar planets.

Tycho Brahe (1546-1601) furnished, by his accurate observations, materials for the work of Kepler.

Johann Kepler (1571-1631) gave further development to the heliocentric hypothesis by discovering the form of planetary orbits and the laws of planetary motions.

Galileo Galilei (1564-1642) taught the twofold motion of the earth and discovered the satellites of Jupiter and the laws of their motions.

The discoveries of Boyle (1627-1691) and of Newton (1642-1727) were as important in the department of physics as were those of Copernicus, Kepler, and Galileo in the department of astronomy. All these, however, are of interest to the student of philosophy principally because of their effect on the course of speculative thought.

Influence of Scientific Discoveries on the Development of Philosophy. The attitude which Catholic and Protestant theologians of the sixteenth century assumed towards the discoveries of Galileo and Kepler is well known. The antagonism, however, between the old and the new modes of thought resulted from a misunderstanding. There is no inherent contradiction between the broad principles of Aristotelian and Scholastic philosophy on the one hand and the new physics and astronomy on the other. Aristotle had advocated the investigation of nature, and the greatest of the schoolmen had insisted on the importance of building a science of nature on the basis of empirical knowledge. St. Thomas, in a remarkable passage, had acknowledged the possible advent of a theory which would subvert the entire structure of Aristotelian astronomy: in reference to the hypotheses (suppositiones) by which the ancient astronomers attempted to explain the irregularities of the motions of the planets, he had written:

Illorum autem suppositiones quas adiuvenerunt non est necessarium esse veras . . . quia forte secundum alium modum nondum ab hominibus comprehensum apparentia circa stellas salvatur.^{1}

The Scholastics, therefore, who attacked the representatives of the new science were false to the principles of their school. Had they known and fully felt the spirit of Aristotelian and Scholastic philosophy they should have put an end to their fruitless discussions, shaken off the yoke of a false method, and gone forth with the representatives of the new science to investigate nature. They should have adopted as their motto "Anteire decet, non subsequi" and taken the lead in the advance guard of discovery. Instead of doing this, they antagonized science, so that when the new age, dominated by the scientific spirit, sought to found a system of metaphysics, it never for a moment considered that in the Aristotelian and Scholastic system of philosophy it already possessed the metaphysics which best accorded with the results of scientific discovery. When, therefore, we study the causes of the misunderstanding between science and Scholastic philosophy, we must lay the burden of the blame on the shoulders of the degenerate representatives of Scholasticism, who, by betraying at the critical moment of its history the great system which they were supposed to defend, did that system a wrong which all the efforts of their successors have not succeeded in righting. The discredit of Scholasticism was due not to a lack of ideas, but to a lack of men to set forth those ideas in the proper light. Moreover (if we are to vindicate Scholasticism at the expense of Scholastics), we must not overlook the dependence of the scientific movement itself on Scholastic philosophy. Humanism grew out of Scholastic soil, and owed more to Scholastic vigor and clearness of thinking than we are commonly aware of. The scientific revival also owes much to the learning of the schools. Columbus and Copernicus, who did more than any of their contemporaries to revolutionize modes of thought, appealed to their contemporaries on the strength of texts from Aristotle and Philolaus. It was by reasoning on the texts of Strabo and Ptolemy that Columbus convinced himself of the existence of a new country beyond the western ocean; and it was by meditating on the glory of God and on the spread of the Christian religion, which he deemed his special vocation in life, that the great mariner acquired the courage to brave the perils of unknown seas. We must keep these facts in mind, and not be too quick to regard the discoveries of this age as out of all relation with the past. Scientific discoveries form no exception to the law that thought flows in a continuous stream from one generation to another.^{2}

FRANCIS BACON

Life. Francis Bacon was the first to attempt the construction of a system of empirical philosophy on the basis of the principles of the new scientific method. He was born in London in 1561. After studying at Cambridge he spent two years in Paris, as companion of the English ambassador. Returning to England, he adopted the legal profession. In 1595 he entered Parliament, became adviser of the crown in 1604, and keeper of the Great Seal in 1617. In 1618 he was made lord chancellor, with the title of Baron Verulam, to which, three years later, that of Viscount St. Albans was added. He was charged, as is well known, with bribery and corruption, and, on pleading guilty to the accusations, was deprived of his office and fined £s;40,000. He died in 1626.

DOCTRINES^{3}

Bacon set himself the task of reorganizing all the branches of scientific knowledge, and with this purpose in view he proposed to expound a new method of scientific study and to treat of each of the sciences with special reference to the making of scientific and practical discoveries. The work in which this plan was to be realized is called the Instauratio Magna, of which the first part, entitled De Dignitate et Augmentis Scientiarum, treats of the reorganization of the sciences, and the second part, entitled Novum Organum, contains the theory of induction and of scientific method. To the sciences themselves, and to their application to discovery, Bacon contributed merely a portion of his projected work, descriptive of natural phenomena, and entitled Historia Naturalis, sive Sylva Sylvarum.

Philosophy has for its object a knowledge of God, nature, and man. Our positive knowledge of God belongs to faith, for reason can give us merely a negative knowledge of God by refuting the objections urged against faith, and by showing the absurdity of atheism. "It is true," Bacon says, in a well known passage in his Essays, "that a little philosophy inclineth men's minds to atheism: but depth in philosophy bringeth men's minds about to religion."^{4}

Bacon distinguishes first philosophy (philosophia prima or scientia universalis), which treats of the concepts and principles underlying all the parts of philosophy, and the philosophy of nature, which is subdivided into speculative and operative, the latter being defined as natural philosophy in its application to mechanics and other arts.^{5}

The first step towards attaining a knowledge of nature consists in purifying the mind by the exclusion of the phantoms, or idols, which interfere with the acquisition of knowledge. The idols, or false appearances, are reduced to four classes: (1) Idols of the tribe. These are common to all men, and are, in some way, derived from the very nature and limitations of the human mind. Such, for example, is the tendency to anthropomorphize. "For the mind," Bacon observes, "is not a plane mirror, but a mirror of uneven surface which combines its own figure with the figures of the objects it represents." (2) Idols of the den. These arise from the peculiar character of the individual. Some minds are naturally analytical, while others are naturally synthetical. To each belongs its own peculiar class of idols of the den. (3) Idols of the market place. These arise from the intercourse of men, and from the peculiarities of language. For words, Bacon warns us, are symbols of conventional value, and are based on the carelessly constructed concepts of the crowd. (4) Idols of the theater. These are false appearances arising from tradition and the authority of schools and teachers.^{6}

Having freed his mind from the false appearances of truth, the searcher after knowledge must next proceed to a personal and active investigation of nature. He must not spin science from his own inner consciousness, as the spider spins its web from its own substance: he must, like the bee, collect material from the world around him and elaborate that material by the process of reflection and meditation. He must observe facts and proceed from the observation of facts to the establishment of laws and axioms. Bacon notes that the "inductia per enumerationem simplicem," of which alone Aristotle and the schoolmen treat, is "scanty and slovenly," because it is based on the observation of positive instances merely, and neglects to take negative instances into account, whereas induction should consider negative instances and instances of difference of degree as well as positive instances. These hints were taken up by John Stuart Mill, to whom we owe the four experimental methods of induction. The chief difference between the Aristotelian and the Baconian induction consists in this, that the former proceeds by accumulation of instances, while the latter is based on the elimination of non-typical instances and the discovery of decisive or "prerogative" instances.^{7}

In his effort to accentuate the importance of the inductive method of acquiring knowledge, Bacon committed the grave error of throwing discredit on the deductive, or syllogistic, process. Failing to recognize that each method has its use, he carried his hostility to the deductive method so far as to refuse to admit on deductive evidence the Copernican system of astronomy.^{8}

Historical Position. Little or nothing has been said of the contents of Bacon's philosophy. Indeed, it is by the method which he inaugurated, rather than by the content of his system of thought, that Bacon is to be judged. His attempts at personal investigation in accordance with the rules which he laid down were, for the most part, crude, and were far less successful than the experiments made by many of his contemporaries.

It was for a long time an axiom almost universally accepted that all the scientific progress made since the days of Bacon was due to the employment of the scientific method which he inaugurated. Recently, however, a more moderate view has begun to prevail. While it is conceded that Bacon deserves exceptional credit for having called attention to the necessity of an active investigation of nature, it is recognized also that he committed a serious mistake in discountenancing the use of deduction. It is historically demonstrable that the hypothetical anticipation of nature, by means of deduction, is as fruitful of scientific discovery as is the use of the inductive method, and Mill, with all his admiration for Bacon's method, acknowledges that no great advance can be made in science except by the alternate employment of induction and deduction. Descartes, who, as we shall see, advocated and used the deductive method, made more important contributions to natural science than did Bacon, the author of what has been called the scientific method.

{1} In Lib. II^um De Coelo, Lect. 17. In the Sum. Theol., Ia, XXXII, 1, ad 2^um, we find the same thought expressed in language almost identical with that of the passage quoted in the text.

{2} Cf. Symonds, The Revival of Learning, pp. 19 ff., and Brother Azarias, Aristotle and the Christian Church, p. 126.

{3} Consult Nichol, Bacon (Blackwood's Philosophical Classics, Edinburgh and Philadelphia, I888); Fischer, Bacon and his Successors, translated by Oxenford (London, 1857). The most recent edition of Bacon's complete works is that by Spedding and Heath (London, 1857 ff.).

{4} Cf. Essay on Atheism (Works, edited by Spedding, Vol. XII, pp. 132 and 337) and Meditation on Atheism (Vol. XIV, p. 93).

{5} Cf. Works, II, 89.

{6} Ibid., I, 250 ff.

{7} Cf. Works, I, 344 ff.

{8} Cf. ibid., VI, 44; IX, 14, 15; X, 422.