If what we are discussing were a point of law or of the humanities, in which neither true nor false exists, one might trust in subtlety of mind and readiness of tongue and in the greater experience of the writers, and expect him who excelled in those things to make his reasoning most plausible, and one might judge it to be the best. But in the natural sciences, whose conclusions are true and necessary and have nothing to do with human will, one must take care not to place oneself in the defense of error; for here a thousand Demostheneses and a thousand Aristotles would be left in the lurch by every mediocre wit who happened to hit upon the truth for himself. Therefore, Simplicio, give up this idea and this hope of yours that there may be men so much more learned, erudite, and well-read than the rest of us as to be able to make that which is false become true in defiance of nature.

If you could see the earth illuminated when you were in a place as dark as night, it would look to you more splendid than the moon.

In the long run my observations have convinced me that some men, reasoning preposterously, first establish some conclusion in their minds which, either because of its being their own or because of their having received it from some person who has their entire confidence, impresses them so deeply that one finds it impossible ever to get it out of their heads. Such arguments in support of their fixed idea as they hit upon themselves or hear set forth by others, no matter how simple and stupid these may be, gain their instant acceptance and applause. On the other hand whatever is brought forward against it, however ingenious and conclusive, they receive with disdain or with hot rage - if indeed it does not make them ill. Beside themselves with passion, some of them would not be backward even about scheming to suppress and silence their adversaries.

Among all the great men who have philosophized about this remarkable effect, I am more astonished at Kepler than at any other. Despite his open and acute mind, and though he has at his fingertips the motions attributed to the earth, he nevertheless lent his ear and his assent to the moon's dominion over the waters, to occult properties, and to such puerilities.

The sun, with all those planets revolving around it and dependent on it, can still ripen a bunch of grapes as if it had nothing else in the universe to do.

I cannot sufficiently admire the eminence of those men's wits, that have received and held it to be true, and with the sprightliness of their judgments offered such violence to their own senses, as that they have been able to prefer that which their reason dictated to them, to that which sensible experiments represented most manifestly to the contrary. ...I cannot find any bounds for my admiration, how that reason was able in Aristarchus and Copernicus, to commit such a rape on their senses, as in despite thereof to make herself mistress of their credulity.

After the publication of my dialogues, I was summoned to Rome by the Congregation of the holy Office, where, being arrived on the 10th of February 1633, I was subjected to the infinite clemency of that tribunal, and of the Sovereign Pontiff, Urban the Eighth; who, notwithstanding, thought me deserving of his esteem.

I am certainly interested in a tribunal in which, for having used my reason, I was deemed little less than a heretic. Who knows but men will reduce me from the profession of a philosopher to that of historian of the Inquisition! But they behave to me in order that I may become the ignoramus and the fool of Italy...

I was obliged to retract, like a good Catholic, this opinion of mine; and as a punishment my dialogue was prohibited; and after five months being dismissed from Rome (at the time that the city of Florence was infected with plague), the habitation which with generous pity was assigned to me, was that of the dearest friend I had in Siena, Monsignor the Archbishop Piccolomini, whose most agreeable conversation I enjoyed with such quite and satisfaction of mind, that having there resumed my studies, I discovered and demonstrated a great number on the mechanical conclusions on the resistance of solids ... after about five months, the pestilence having ceased, the confinement of that house was changed by His Holiness for the freedom of the country so agreeable to me, whence I returned to the villa of Bellosguardo, and afterwards to Arcetri, where I still breathe salubrious air near my dear native-country Florence.

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.

I am quite convinced; and, believe me, if I were again beginning my studies, I should follow the advice of Plato and start with mathematics, a science which proceeds very cautiously and admits nothing as established until it has been rigidly demonstrated.

My purpose is to set forth a very new science dealing with a very ancient subject. There is, in nature, perhaps nothing older than motion, concerning which the books written by philosophers are neither few nor small; nevertheless I have discovered by experiment some properties of it which are worth knowing and which have not hitherto been either observed or demonstrated. Some superficial observations have been made, as, for instance, that the free motion [naturalem motum] of a heavy falling body is continuously accelerated; but to just what extent this acceleration occurs has not yet been announced; for so far as I know, no one has yet pointed out that the distances traversed, during equal intervals of time, by a body falling from rest, stand to one another in the same ratio as the odd numbers beginning with unity.

It has been observed that missiles and projectiles describe a curved path of some sort; however no one has pointed out the fact that this path is a parabola. But this and other facts, not few in number or less worth knowing, I have succeeded in proving; and what I consider more important, there have been opened up to this vast and most excellent science, of which my work is merely the beginning, ways and means by which other minds more acute than mine will explore its remote corners.

This [experimentation] is the custom-and properly so-in those sciences where mathematical demonstrations are applied to natural phenomena, as is seen in the case of perspective, astronomy, mechanics, music, and others where the principles, once established by well-chosen experiments, become the foundations of the entire superstructure.

See now the power of truth; the same experiment which at first glance seemed to show one thing, when more carefully examined, assures us of the contrary.

Indeed, I think we may concede to our Academician, without flattery, his claim that in the principle [principio, i. e., accelerated motion] laid down in this treatise he has established a new science dealing with a very old subject. Observing with what ease and clearness he deduces from a single principle the proofs of so many theorems, I wonder not a little how such a question escaped the attention of Archimedes, Apollonius, Euclid and so many other mathematicians and illustrious philosophers, especially since so many ponderous tomes have been devoted to the subject of motion.

If I shall have sufficient strength to improve and amplify what was written and published by me up to now about motion by adding some little speculations, and in particular those relating to the force of percussion, in the investigation of which I have consumed hundreds and thousands of hours, and finally reduced this to very easy explanation, so that people can understand it in less than half an hour of time.

I esteem myself happy to have as great an ally as you in my search for truth. I will read your work ... all the more willingly because I have for many years been a partisan of the Copernican view because it reveals to me the causes of many natural phenomena that are entirely incomprehensible in the light of the generally accepted hypothesis. To refute the latter I have collected many proofs, but I do not publish them, because I am deterred by the fate of our teacher Copernicus who, although he had won immortal fame with a few, was ridiculed and condemned by countless people (for very great is the number of the stupid).

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.

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?

We seek not what God could have done but what He has done.... God could have caused birds to fly with bones of solid gold, with veins full of quicksilver, with flesh heavier than lead and very small and heavy wings, so as to better show His power ... but He wanted to make their bones, flesh and feathers very light ... to teach us that He likes simplicity and ease.

I have been in my bed for five weeks, oppressed with weakness and other infirmities from which my age, seventy four years, permits me not to hope release.

Alas! Your dear friend and servant Galileo has been for the last month hopelessly blind; so that this heaven, this earth, this universe, which I by my marvelous discoveries and clear demonstrations had enlarged a hundred thousand times beyond the belief of the wise men of bygone ages, henceforward for me is shrunk into such a small space as is filled by my own bodily sensations.

Wine is a mixture of moisture and light.

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.

All truths are easy to understand once they are discovered; the point is to discover them.

I have never met a man so ignorant that I could not learn something from him.

What we may be witnessing is not just the end of the Cold War, or the passing of a particular period of post-war history, but the end of history as such ... That is, the end point of mankind's ideological evolution and the universalization of Western liberal democracy as the final form of human government.

There is an unquestionable relationship between economic development and liberal democracy, which one can observe simply by looking around the world. But the exact nature of that relationship is more complicated than it first appeared, and is not adequately explained by any of the theories presented up to this point. The logic of modern natural science and the industrialization process it fosters does not point in a single direction in the sphere of politics, as it does in the sphere of economics. Liberal democracy is compatible with industrial maturity, and is preferred by the citizens of many industrially advanced states, but there does not appear to be a necessary connection between the two. The Mechanism underlying our directional history leads equally well to a bureaucratic-authoritarian future as to a liberal one. We will therefore have to look elsewhere in trying to understand the current crisis of authoritarianism and the worldwide democratic revolution.

Experience suggests that if men cannot struggle on behalf of a just cause because that just cause was victorious in an earlier generation, then they will struggle against the just cause. They will struggle for the sake of struggle. They will struggle, in other words, out of a certain boredom: for they cannot imagine living in a world without struggle. And if the greater part of the world in which they live is characterized by peaceful and prosperous liberal democracy, then they will struggle against that peace and prosperity, and against democracy. p. 330

Neoconservatives believed that history can be pushed along with the right application of power and will. Leninism was a tragedy in its Bolshevik version, and it has returned as farce when practiced by the United States. Neoconservatism, as both a political symbol and a body of thought, has evolved into something I can no longer support. ..."War" is the wrong metaphor for the broader struggle, since wars are fought at full intensity and have clear beginnings and endings. Meeting the jihadist challenge is more of a "long, twilight struggle" whose core is not a military campaign but a political contest for the hearts and minds of ordinary Muslims around the world.

The End of History was never linked to a specifically American model of social or political organisation. Following Alexandre Kojève, the Russian-French philosopher who inspired my original argument, I believe that the European Union more accurately reflects what the world will look like at the end of history than the contemporary United States. The EU's attempt to transcend sovereignty and traditional power politics by establishing a transnational rule of law is much more in line with a "post-historical" world than the Americans' continuing belief in God, national sovereignty, and their military.

Be afraid of the Chinese. I mean, the Chinese shoot down satellites in space; they hack into Google's computers; the Osama bin Laden people can't make their underwear blow up.

The Left's identity politics poses a threat to free speech and to the kind of rational discourse needed to sustain a democracy... The focus on lived experience by identity groups prioritizes the emotional world of the inner self over the rational examination of issues in the outside world and privileges sincerely held opinions over a process of reasoned deliberation that may force one to abandon prior opinions.

The limits of this strategy were evident as the century drew to a close.

The more progress that has been made toward eradicating social injustices, the more intolerable the remaining injustices seem, and thus the moral imperative to mobilizing to correct them.

Liberal values like tolerance and individual freedom are prized most intensely when they are denied: People who live in brutal dictatorships want the simple freedom to speak, associate, and worship as they choose. But over time life in a liberal society comes to be taken for granted and its sense of shared community seems thin.

Putin told the Financial Times that liberalism has become an "obsolete" doctrine. While it may be under attack from many quarters today, it is in fact more necessary than ever. It is more necessary because it is fundamentally a means of governing over diversity, and the world is more diverse than it ever has been. Democracy disconnected from liberalism will not protect diversity, because majorities will use their power to repress minorities.

In situations of de facto diversity, attempts to impose a single way of life on an entire population is a formula for dictatorship.

Progressives on the left have shown themselves willing to abandon liberal values in pursuit of social justice objectives. There has been a sustained intellectual attack on liberal principles over the past three decades coming out of academic pursuits like gender studies, critical race theory, postcolonial studies, and queer theory, that deny the universalistic premises underlying modern liberalism. The challenge is not simply one of intolerance of other views or "cancel culture" in the academy or the arts. Rather, the challenge is to basic principles that all human beings were born equal in a fundamental sense, or that a liberal society should strive to be color-blind.

It is hard to see how the discarding of liberal values is going to lead to anything in the long term other than increasing social conflict and ultimately a return to violence as a means of resolving differences.

The pragmatic justification is that liberalism is... a political doctrine that seeks to enable societies to govern themselves over diversity. It arose in the minds of thinkers like Thomas Hobbes or John Locke or Samuel Pufendorf... as a result of the European wars of religion following the Protestant Reformation.

In the Thirty Years' War... a third of the population of central Europe were killed in a bloody struggle between different Christian religious sects, and the pragmatic part of liberalism was to take final ends [defined by religions] out of political discussion... and to lower the sights of politics to defend life itself, and not "the good life"... as defined by a particular sect of a particular religion.

Therefore tolerance of diversity, of people that don't believe the same thing that you do, has always been at the core of this pragmatic project to enable diverse populations to live with one another.

That liberal world that emerged after 1945 led to one of the most spectacularly successful periods in human history. There was material progress. There was stability. There was human freedom. There was the flourishing of many human activities that can only take place in a liberal, and therefore free society...

After World War II, liberal rights were not something that were only deserved by white Europeans. ...There was a recognition that the black and brown peoples being held in colonial bondage could not consistently be held in that bondage, because liberalism was a universal doctrine. ...That's the other respect in which we can defend liberalism, a moral one.

Liberalism is... a protection of human autonomy.

The idea of universal human dignity ultimately comes out of Christianity... the view that all human beings are equal in the sight of God because they have the capacity for moral choice. As Western thought developed in the 17th-18th centuries, this took on a secular form under thinkers like Jean-Jacques Rousseau or Immanuel Kant or Georg Hegel, who argued that human equality is... based on human autonomy.

In Kant's words, human beings are uncaused causes, and therefore have infinite value, and a liberal regime protects that autonomy by giving people rights... The right to speak, to organize, to associate, and ultimately to have a share of power by being able to vote. ...This is ...the moral status, the dignity that life in a liberal regime that does respect individual rights, gives us, and it is one of the reasons that to this day, people do not want to live in authoritarian countries that do not recognize the fundamental dignity of their... citizens.

For both the pragmatic... and... moral reasons... liberalism became the dominant doctrine of the 20th century, and should... continue to be defended....