234 



DISCOVERY 



replv that Galileo was an Italian astronomer who 

 taught that the earth was round and not flat ; that it 

 circled round the sun instead of being stationary ; 

 and that when tortured by the Roman Inquisition and 

 made to recant he muttered between his teeth, "Eppiir 

 si inuove." Marks would be low, for the good 

 Galileo never was put to the torture, and he never 

 said " Eppur si iiiiiore." Xor did the mediaeval 

 astronomers teach the earth was flat. I imagine 

 there are but few readers of Dante's Vita Xuova 

 nowadays who are not made to sit up when they 

 discover that to understand the reference to Beatrice's 

 age in the very first paragraph, a knowledge of the 

 precession of the equinoxes is necessary — an 

 astronomical phenomenon known to every mediaeval 

 student, although regarded from a geocentric stand- 

 point. If there is one thing more than another 

 which distinguishes the modern from the mediaeval 

 student, it is his ignorance of practical astronomy — 

 of the apparent motions of the heavenly bodies. If 

 anyone would form a conception of the astronomical 

 knowledge of the mediaeval scholar, let him get a sight 

 of the perpetual almanack compiled by Profacius 

 (Machir Ben Tibbon)' of the University of Mont- 

 pellier, in the latter half of the thirteenth century, 

 from which the courses of the moon and planets and 

 their eclipses might be foretold at any given date 

 from 1300 onward. .\s early as the fourth century, 

 tables and rules were extant bv which the days and 

 hours of eclipses were accurately calculated. And if 

 one remembers that such calculations were rendered 

 much more complicated and difficult by being based 

 on a geocentric theory of the universe, one's respect 

 for the precision and range of early astronomy will 

 be tenfold. Pre-Galilean astronomy from the days of 

 Hipparchus to Ptolemy and Alphraganus had been 

 elaborated and perfected during the progress of 

 eighteen centuries ; it adequately explained the 

 apparent phenomena and served all practical purposes 

 of civil life — an astronomy rendered almost sacred 

 to the mediaeval mind by the infallible authority of 

 .Aristotle — an astronomy which Sir Thomas Browne 

 regarded as a proof of God's wisdom, and w-hich 

 Bacon refused to reject in favour of the Galilean 

 theory. Besides its practical uses there was another 

 reason why the mediaeval mind was absorbed in the 

 contemplation of the heavenly bodies and their 

 wandering paths, and why the astrologer sought to 

 fathom the sweet influences of the Pleiades — their 

 supposed infallible influence on mortal life and 

 destiny. 



How much longer geocentric astronomy would have 

 persisted if a Dutch spectacle-maker's apprentice had 

 not, while playing with some lenses, discovered that 

 by placing two of them at intervals distant objects 

 became nearer, none can tell ; but to a young pro- 



fessor of mathematics at Padua the toy became a 

 key to a startling new reading of the heavens. 



" In .August i6og," writes the Venetian diarist 

 Priuli, " I climbed the campanile of St. Mark with 

 the excellent Galileo and Signor Contarini, to see the 

 marvels of the said Galileo's new tube. Closing one 

 eye and looking through the other each of us saw 

 distinctly Fusina and Chioggia, and even Conegliano, 

 and folk entering and leaving the church at Murano, 

 with many other details truly marvellous to behold." 

 Marvellous and indeed revolutionary ! Imagine what 

 would be the feelings of our scientists of to-day if a 

 new discovery w'ere to render obsolete all modern 

 physical science, vitiate our heliocentric astronomy, 

 make all our text-books and professors back numbers : 

 .some conception may then be formed of the feelings 

 of the mathematicians of Galileo's time. There i.s. 

 nothing absolute in what is termed scientific truth. 

 Our system is true so long' as it satisfactorily explains 

 phenomena as we know them, and that is precisely 

 what the geocentric system did in pre-Copernican 

 days, and did it more satisfactorily than Galileo's new- 

 theory. Galileo was a born controversialist, and 

 employed with masterly skill that grave and eloquent 

 irony which Carducci says so splendidly closes the 

 great literature of the sixteenth century. This and 

 his mordant sarcasm were ill calculated to win over 

 opponents. He thus trounces a learned classical 

 senior who quoted Suidas in proof of a theory on the 

 nature of heat — Suidas who stated that the Baby- 

 lonians used to cook eggs by whirling them quickly in 

 a sling. " Of course, if I am told I must believe this 

 I will, but I can't help saying this much. If we don't 

 succeed in producing an effect that was successfully 

 produced in earlier times some element of success 

 must be lacking, and this element must be vital. 

 Now we have eggs and slings and stout fellows to 

 swing them. Vet the eggs don't cook; on the con- 

 trary, if they were hot the swinging would more 

 quickly cool them. Therefore, since all that is lack- 

 ing to us is that we are not Babylonians, it follows 

 that the fact of being Babylonians is the eft'ectivc 

 cause of the eggs cooking, and not the attrition of 

 the air — which is what I set out to prove." 



Contrary to what is generally believed, Galileo was 

 first Ijrought up, not against the Church, but against 

 the mathematicians and Aristotelians — Aristotle who, 

 as students of Dante will know, was authoritative in 

 medieval schools. If Aristotle said a thing, like John 

 Bull, it was so. " I was one day," says Galileo, " at 

 a physician's house at Venice who was giving a lesson 

 in anatomy. Having dissected and traced the nervous 

 system to its origin in the brain, and its extension 

 through the spinal cord and its ramifications through 

 the human body, a sceptical -Aristotelian present said, 

 • \\m have demonstrated this so clearly to my senses. 



' Edited and published at Florence in 1908. 



Frammenii, p. 66. 



