There are those who reason well, but they are greatly outnumbered by those who reason badly. Galileo Galilei More Quotes by Galileo Galilei More Quotes From Galileo Galilei I would beg the wise and learned fathers (of the church) to consider with all diligence the difference which exists between matters of mere opinion and matters of demonstration. ... [I]t is not in the power of professors of the demonstrative sciences to alter their opinions at will, so as to be now of one way of thinking and now of another. ... [D]emonstrated conclusions about things in nature of the heavens, do not admit of being altered with the same ease as opinions to what is permissible or not, under a contract, mortgage, or bill of exchange. Galileo Galilei nature wise father It has always seemed to me extreme presumptuousness on the part of those who want to make human ability the measure of what nature can and knows how to do, since, when one comes down to it, there is not one effect in nature, no matter how small, that even the most speculative minds can fully understand. Galileo Galilei nature mind want Vision, I say, is related to light itself. But of this sensation and the things pertaining to it, I pretend to understand but little; and since even a long time would not suffice to explain that trifle, or even to hint at an explanation, I pass over this in silence. Galileo Galilei silence light long But what exceeds all wonders, I have discovered four new planets and observed their proper and particular motions, different among themselves and from the motions of all the other stars; and these new planets move about another very large star [Jupiter] like Venus and Mercury, and perchance the other known planets, move about the Sun. As soon as this tract, which I shall send to all the philosophers and mathematicians as an announcement, is finished, I shall send a copy to the Most Serene Grand Duke, together with an excellent spyglass, so that he can verify all these truths. Galileo Galilei stars science moving Nothing can be taught to a man, only it's possibly to help him to discover it inside. Galileo Galilei taught helping men They know that it is human nature to take up causes whereby a man may oppress his neighbor, no matter how unjustly. ... Hence they have had no trouble in finding men who would preach the damnability and heresy of the new doctrine from the very pulpit. Galileo Galilei doctrine men religion One can understand nature only when one has learned the language and the signs in which it speaks to us; but this language is mathematics and these signs are methematical figures. Galileo Galilei mathematics language speak Philosophy [nature] is written in that great book which ever is before our eyes -- I mean the universe -- but we cannot understand it if we do not first learn the language and grasp the symbols in which it is written. The book is written in mathematical language, and the symbols are triangles, circles and other geometrical figures, without whose help it is impossible to comprehend a single word of it; without which one wanders in vain through a dark labyrinth. Galileo Galilei philosophy mean book To excite in us tastes, odors, and sounds I believe that nothing is required in external bodies except shapes, numbers, and slow or rapid movements. ... if ears, tongues, and noses were removed, shapes and numbers and motions would remain, but not odors or tastes or sounds. Galileo Galilei sound numbers believe I therefore concluded, and decided unhesitatingly, that there are three stars in the heavens moving about Jupiter, as Venus and Mercury about the Sun; which at length was established as clear as daylight by numerous other observations. Galileo Galilei stars science moving What has philosophy got to do with measuring anything? It's the mathematicians you have to trust, and they measure the skies like we measure a field. Galileo Galilei fields sky philosophy That sculpture is more admirable than painting for the reason that it contains relief and painting does not is completely false. ... Rather, how much more admirable the painting must be considered, if having no relief at all, it appears to have as much as sculpture! Galileo Galilei sculpture relief doe The theologians also should not be irritated. For if they find that this opinion is false, then they would be free to condemn it; and if they discover that it is true, they ought to thank those who have opened the way to finding the true sense of the Scriptures and who have prevented them from falling into the grave scandal of condemning a true proposition. Galileo Galilei scandal would-be fall I cannot but be astonished that Sarsi should persist in trying to prove by means of witnesses something that I may see for myself at any time by means of experiment. Witnesses are examined in doutbful matters which are past and transient, not in those which are actual and present. A judge must seek by means of witnesses to determine whether Peter injured John last night, but not whether John was injured, since the judge can see that for himself. Galileo Galilei truth science mean My dear Kepler, what would you say of the learned here, who, replete with the pertinacity of the asp, have steadfastly refused to cast a glance through the telescope? What shall we make of this? Shall we laugh, or shall we cry? Galileo Galilei kepler telescopes laughing Their vain presumption of knowing all can take beginning solely from their never having known anything; for if one has but once experienced the perfect knowledge of one thing, and truly tasted what it is to know, he shall perceive that of infinite other conclusions he understands not so much as one. Galileo Galilei knowing science knowledge The Grand Duke [of Tuscany] ...after observing the Medicaean plants several times with me ... has now invited me to attach myself to him with the annual salary of one thousand florins, and with the title of Philosopher and Principal Mathematicial to His Highness; without the duties of office to perform, but with the most complete leisure; so that I can complete my Treatises. Galileo Galilei dukes office science Spots are on the surface of the solar body where they are produced and also dissolved, some in shorter and others in longer periods. They are carried around the Sun; an important occurrence in itself. Galileo Galilei body important science Names and attributes must be accommodated to the essence of things, and not the essence to the names, since things come first and names afterwards. Galileo Galilei essence names firsts Well, since paradoxes are at hand, let us see how it might be demonstrated that in a finite continuous extension it is not impossible for infinitely many voids to be found. Galileo Galilei void might hands
