If a man of science, when he wishes to publish to the world a discovery or a hypothesis, adopts the form of a dialogue as a method of stating his case, he ought in all reason to do full justice to the antagonistic side, and state his opponent’s case as well as his own. I fear that Galileo failed to do this, not only in this particular dialogue, but also to some extent in those of the three preceding days. Simplicio, as I said above, is not a fool, but as a personage in a scientific argument he is lamentably deficient.
Simplicio at the end of the Dialogue urges that God could, in His infinite power, cause the tides by some other means than those suggested by Salviati, to which true and pious (though, perhaps, rather irrelevant) argument the latter respectfully and devoutly assents.
The concluding sentences are said, as I have remarked elsewhere, to have been recast or retouched by Father Riccardi.
It is worth noticing that there is a passage in the fourth day’s dialogue, in which the author alludes to the fact of the Sun being apparently longer by about nine days in passing along the ecliptic from the spring to the autumn equinox, than in passing from the autumnal to the vernal; that is to say, of the northern hemisphere having so much longer summer than winter, and he treats it as one of the recondite problems of astronomy not as yet understood. This is an additional proof that for some reason or another he had not made himself acquainted with Kepler’s researches; for as soon as it became known that the planets move, not in circles, but in ellipses, with the Sun in one of the foci, it was obvious that there would be in every case (though in some more than others) this inequality to which allusion has been made, and the Earth, if a planet, would be subject to the same rule as the rest.
Such, then, is a somewhat imperfect précis of this famous work of Galileo, which owes its importance to the historical circumstances connected with its publication quite as much, to say the least of it, as to its own intrinsic merit.
CHAPTER IV.
Resuming the history of events, we find that early in the year 1632 the printing of the Dialogue was completed. The author caused some copies to be bound and gilt and sent to Rome. It was not easy to pass them, on account of the quarantine; yet some amongst them found their way, and great was the sensation caused in the ecclesiastical world by their appearance.
There were a few admirers of Galileo who approved warmly; but there was the School of Aristotle, as in these enlightened days there is the School of Darwin,[14] and they could not bear that anything should be published reflecting on the scientific infallibility of their great philosopher. Thus we find that Father Scheiner, writing to Gassendi, observed that Galileo had written his work “contra communem Peripateticorum Scholam.”
The agitation against the book was successful, and a report arose forthwith that it would be condemned. The report was no mere canard, as the subsequent proceedings soon showed. In the month of August of this same year the Master of the Sacred Palace gave orders to the printer at Florence to suspend the distribution of the copies, and he also sent for those which had been brought to Rome. Nor was this all. In the following month the Pope ordered that a letter should be written to the Inquisitor of Florence, enjoining him to direct Galileo to present himself in Rome in the month of October, in order to explain his conduct.