On the 7th of January, 1610, at one o'clock in the morning, when Galileo directed his telescope to Jupiter, he observed three stars near the body of the planet, two being to the east and one to the west of him. They were all in a straight line, and parallel to the ecliptic and appeared brighter than other stars of the same magnitude. Believing them to be fixed stars, he paid no great attention to their distances from Jupiter and from one another. On the 8th of January, however, when, from some cause or other, he had been led to observe the stars again, he found a very different arrangement of them; all the three were on the west side of Jupiter, nearer one another than before and almost at equal distances. Though he had not turned his attention to the extraordinary fact of the mutual approach of the stars, yet he began to consider how Jupiter could be found to the east of the three stars, when but the day before he had been to the west of two of them. The only explanation which he could give of this fact was that the motion of Jupiter was direct, contrary to the astronomical calculations, and that he had got before these two stars by his own motion.

In this dilemma between the testimony of his senses and the results of calculation, he waited for the following night with the utmost anxiety, but his hopes were disappointed, for the heavens were wholly veiled in clouds. On the 10th, two only of the stars appeared, and both on the east side of the planet. As it was obviously impossible that Jupiter could have advanced from west to east on the 8th of January, and from east to west on the 10th, Galileo was forced to conclude that the phenomenon which he had observed arose from the motion of the stars, and he set himself to observe diligently their change of place. On the 11th there were still only two stars, and both to the east of Jupiter, but the more eastern star was now twice as large as the other one, though on the preceding night they had been perfectly equal. This fact threw a new light on Galileo's difficulties, and he immediately drew the conclusion, which he considered to be indubitable, "that there were in the heavens three stars which revolve around Jupiter, in the same manner as Venus and Mercury revolve around the sun.' On the 12th of January he again observed them in new positions, and of different magnitudes; and on the 13th he discovered a fourth star, which completed the four secondary planets with which Jupiter is surrounded.

207. The Abjuration of Galileo

(Routledge, R., History of Science, p. 123. London, 1881)

The Copernican theory made a strong appeal to Galileo, and he expounded it with much fervor. For this he was called to Rome by the Cardinals of the Inquisition, in 1615, who pronounced sentence (Routledge, pp. 119-22) against him; condemned the Copernican theory as "absurd in philosophy" and "expressly contrary to Holy Scripture"; and compelled him to recant (1616). On the election of a new Pope who had been Galileo's friend he thought that, under the changed conditions, he might now be permitted larger liberty, and in 1632 he published his celebrated Dialogue on the Two Chief Systems of the World, the Ptolemaic and the Copernican, in which he took the Ptolemaic side, but upheld it only feebly. For this he was again called to Rome, and compelled by the Inquisitorial body to recant and abjure, as follows:

I, Galileo Galilei, son of the late Vicenzo Galilei of Florence, aged seventy years, being brought personally to judgment, and kneeling before you, Most Eminent and Most Reverend Lords Cardinals, General Inquisitors of the universal Christian Republic against heretical depravity, having before my eyes the Holy Gospels, which I touch with my own hands, swear, that I have always believed, and now believe, and with the help of God will in future believe, every article which the Holy Catholic and Apostolic Church of Rome holds, teaches, and preaches. But because I had been enjoined by this Holy Office altogether to abandon the false opinion which maintains that the sun is the center and immovable, and forbidden to hold, defend, or teach the said false doctrine in any manner, and after it had been signified to me that the said doctrine is repugnant with the Holy Scripture, I have written and printed a book, in which I treat of the same doctrine now condemned, and adduce reasons with great force in support of the same, without giving solution, and therefore have been judged grievously suspected of heresy; that is to say, that I held and believed that the sun is the center of the world and immovable, and that the sun is not the center and moveable.

Wishing, therefore, to remove from the minds of your Eminences, and of every Catholic Christian, this vehement suspicion rightfully entertained towards me, with a sincere heart and unfeigned faith, I abjure, curse, and detest the said errors and heresies, and generally every other error and sect contrary to the said Holy Church; and I swear that I will never more in future say or assert anything verbally, or in writing, which may give rise to a similar suspicion of me; but if I shall know any

heretic, or any one suspected of heresy, that I will denounce him to this Holy Office, or to the Inquisitor and Ordinary of the place in which I may be.

I swear, moreover, and promise, that I will fulfil, and observe fully, all the penances which have been or shall be laid to me by this Holy Office. But if it shall happen that I violate any of my said promises, oaths, and protestations (which God avert!), I subject myself to all the pains and punishments which have been decreed and promulgated by the sacred canons, and other general and particular constitutions, against delinquents of this description. So may God help me, and His Holy Gospels, which I touch with my own hands.

I, the above-named Galileo Galilei, have abjured, sworn, promised, and bound myself, as above, and in witness thereof with my own hand have subscribed this present writing of my abjuration, which I have recited word for word. At Rome in the Convent of Minerva, 22d June, 1633.

I, Galileo Galilei, have abjured as above with my own hand.

208. Francis Bacon on Scientific Progress

(Francis Bacon, Novum Organum, book 1, lxxxviii-xc)

The great service of Francis Bacon to modern science lay in the formulation and statement of the inductive method of work and thinking, and in pointing out the vast field of usefulness of such a method in discovering truth. This he did in his Novum Organum, published in 1620, so named because he regarded it as a great improvement over the deductive Organon of Aristotle, which had dominated all thinking during the later Middle Ages. In the following extract from this work Bacon sets forth the difficulties encountered by those who propose the use of new means of arriving at truth.

We cannot, therefore, wonder that no magnificent Discoveries, worthy of mankind, have been brought to light, whilst men are satisfied and delighted with such scanty and puerile tasks, nay even think that they have pursued or attained some great object in their accomplishment.

lxxxix. Nor should we neglect to observe that Natural Philosophy has, in every age, met with a troublesome and difficult opponent: I mean Superstition, and a blind and immoderate zeal for Religion. For

we see that among the Greeks those who first disclosed the natural causes of Thunder and Storms to the yet untrained ears of man, were condemned as guilty of impiety towards the Gods. Nor did some of the old Fathers of Christianity treat those much better who showed by the most positive proofs (such as no one now disputes) that the Earth is spherical, and thence asserted that there were Antipodes.

Even in the present state of things the condition of discussions on Natural philosophy is rendered more difficult and dangerous by the Summaries and Methods of Divines, who, after reducing Divinity into such order as they could, and bringing it into a Scientific form, have proceeded to mingle an undue proportion of the contentious and thorny Philosophy of Aristotle with the Substance of Religion.

xc. Again, in the habits and regulations of Schools, Universities, and the like Assemblies, destined for the abode of learned men, and the improvement of learning, everything is found to be opposed to the progress of the Sciences. For the Lectures and Exercises are so ordered, that any thing out of the common track can scarcely enter the thoughts and contemplations of the mind. If, however, one or two have perhaps dared to use their liberty, they can only impose the labour on themselves, without deriving any advantage from the association of others: and if they put up with this, they will find their industry and spirit of no slight disadvantage to them in making their fortune. For the Pursuits of men in such situations are, as it were, chained down to the writings of particular Authors, and if any one dare to dissent from them, he is immediately attacked as a turbulent and revolutionary spirit. Yet how great is the difference between Civil Matters and the Arts; for there is not the same danger from new activity and new light. In Civil matters even a change for the better is suspected on account of the commotion it occasions; for Civil government is supported by authority, unanimity, fame, and public opinion, and not by demonstration. In the Arts and Sciences, on he contrary, every department should resound, as in mines, with new Works and advances. And this is the Rational, though not the actual, view of the case: for that administration and Government of Science we have spoken of, is wont too rigorously to repress its growth.

209. The Importance of Bacon's Work

(T. B. Macaulay, Essay on Lord Bacon; Edinburgh Review, July, 1837) The following summary states well the importance of the work done by Bacon in formulating the inductive method of study.

... Bacon was not, as we have already seen, the inventor of the inductive method. He was not even the person who first analyzed the inductive method correctly, though he undoubtedly analyzed it more

minutely than any who preceded him. He was not the person who first showed that by the inductive method alone new truth could be discovered. But he was the person who first turned the minds of speculative men, long occupied in verbal disputes, to the discovery of new and useful truth; and, by doing so, he at once gave to the inductive method an importance and dignity which had never before belonged to it. He was not the maker of that road; he was not the discoverer of that road; he was not the person who first surveyed and mapped that road. But he was the person who first called the public attention to an inexhaustible mine of wealth, which had been utterly neglected, and which was accessible by that road alone. By doing so, he caused that road, which had previously been trodden only by peasants and higglers, to be frequented by a higher class of travellers.

By stimulating men to the discovery of new truth, Bacon stimulated them to employ the inductive method, the only method, even the ancient philosophers and the schoolmen themselves being judges, by which new truth can be discovered. By stimulating men to the discovery of useful truth, he furnished them with a motive to perform the inductive process well and carefully. His predecessors had been, in his phrase, not interpreters, but anticipators of nature. They had been content with the first principles at which they had arrived by the most scanty and slovenly induction. And why was this? It was, we conceive, because their philosophy proposed to itself no practical end, because it was merely an exercise of the mind. A man who wants to contrive a new machine or a new medicine has a strong motive to observe accurately and patiently, and to try experiment after experiment. But a man who merely wants a theme for disputation or declamation has no such motive. He is therefore content with premises grounded on assumption, or on the most scanty and hasty induction. Thus, we conceive, the schoolmen acted. On their foolish premises they often argued with great ability; and as their object was "assensum subjugare, non res," to be victorious in controversy, not to be victorious over nature, they were consistent. For just as much logical skill could be shown in reasoning on false as on true premises. But the followers of the new philosophy, proposing to themselves the discovery of useful truth as their object, must have altogether failed of attaining the object if they had been content to build theories on superficial induction.

What Bacon did for inductive philosophy may, we think, be fairly stated thus. The objects of preceding speculators were objects which could be attained without careful induction. Those speculators, therefore, did not perform the inductive process carefully. Bacon stirred up men to pursue an object which could be attained only by induction, and