Carl Sagan Quotes

Agnosticism, in fact, is not a creed, but a method, the essence of which lies in the rigorous application of a single principle. ... Positively the principle may be expressed: In matters of the intellect, follow your reason as far as it will take you, without regard to any other consideration. And negatively: In matters of the intellect, do not pretend that conclusions are certain which are not demonstrated or demonstrable.

The starting-point and chief principle of every science, and hence of theology also, is not only methodical doubt, but positive doubt. One can believe only what one has perceived to be true from reasonable grounds, and consequently one must have the courage to continue doubting until one has found reliable grounds to satisfy the reason.

The very essence of rationalism is that it assumes that the reason is the highest faculty in man and the lord of all the rest.

I will live by the standard of reason, and if thinking in accordance with reason takes me to perdition, then I will go to hell with my reason rather than to heaven without it.

The whole of science is nothing more than a refinement of everyday thinking.

It is not rational to assume, without evidence, that rationality can disclose everything about the world, just because it can disclose some things. Our intuition in favour of rationality, where we are inclined to use it, is just that - an intuition. Reason is founded in intuition and ends in intuition, like a pair of massive bookends.

Everything must justify its existence before the judgment seat of Reason, or give up existence.

Those who invalidate reason ought seriously to consider whether they argue against reason with or without reason.

I do not feel obliged to believe that the same God who has endowed us with senses, reason and intellect has intended us to forego their use and by some other means to give us knowledge which we can attain by them.

Science is not wisdom.

The weakness of human reason appears more evidently in those who know it not than in those who know it.

Belief has no place as far as science reaches, and may be first permitted to take root where science stops.

Now is the time for everyone who believes in the rule of reason to speak up against pathological science and its purveyors.

On the road halfway between faith and criticism stands the inn of reason. Reason is faith in what can be understood without faith, but it's still a faith, since to understand presupposes that there's something understandable.

Epistemology without contact with science becomes an empty scheme. Science without epistemology is-insofar as it is thinkable at all-primitive and muddled.

Reason is the shepherd trying to corral life's vast flock of wild irrationalities.

If faith is a valid tool of knowledge, then anything can be true 'by faith,' and therefore nothing is true. If the only reason you can accept a claim is by faith, then you are admitting that the claim does not stand on its own merits.

Finding bad reasons for what one believes for other bad reasons - that's philosophy.

Reason is so unreasonable, that few people can say they are in possession of it.

Most geometricians, chemists, mathematicians, and great scientists submit religion to reason only to discover a problem as unsolvable as that of squaring a circle.

It has often been said, and certainly not without justification, that the man of science is a poor philosopher.

Science teaches us, in effect, to submit our reason to the truth and to know and judge of things as they are-that is to say, as they themselves choose to be and not as we would have them to be.

Expose every belief to the light of reason, discourse, facts, scientific observations; question everything, be sceptical because this is the only chance at life you will ever get.

Science tells us what we have reason to believe. Not what we have a duty to believe. Not what experts, in their pontificating wisdom, instruct us to believe... No, science tells us what there is good reason to believe.

There is more religion in men's science, than there is science in their religion.