C. S. Lewis Quotes

Through logic and inference we can prove anything. Therefore, logic and inference, in contrast to ordinary daily living experience, are secondary instruments of knowledge. Probably tertiary.

Bad reasoning as well as good reasoning is possible; and this fact is the foundation of the practical side of logic.

Implication is thus the very texture of our web of belief, and logic is the theory that traces it.

Logic teaches rules for presentation, not thinking.

From a drop of water a logician could infer the possibility of an Atlantic or a Niagara without having seen or heard of one or the other.

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.

Logic can become enormously difficult, and it would undoubtedly be well to produce more assurance in its use.

To reason logically is so to link one's propositions that each should contain the reason for the one succeeding it, and should itself be demonstrated by the one preceding it. Or at any rate, whatever the order adopted in the construction of one's own exposition, it is to demonstrate judgments by each other.

Sometimes they reasoned thus: "The Messiah ought to do such a thing, now Jesus is the Messiah, therefore Jesus has done such a thing." At other times, by an inverse process, it was said: "Such a thing has happened to Jesus; now Jesus is the Messiah; therefore such a thing was to happen to the Messiah."

Physics is a good framework for thinking. ... Boil things down to their fundamental truths and reason up from there.

That's the way most everyone gets here. It's really quite simple: every time you decide something without having a good reason, you jump to Conclusions whether you like it or not. It's such an easy trip to make that I've been here hundreds of times.

Belief cannot be reckoned with in terms of science, for science and faith are mutually exclusive.

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.

Why understand when you can believe?

The claim is also sometimes made that science is as arbitrary or irrational as all other claims to knowledge, or that reason itself is an illusion. As Ethan Allen said Those who invalidate reason ought seriously to consider whether they argue against reason with or without reason; if with reason, then they establish the principle that they are labouring to dethrone. If they argue without reason, which they must do, in order to be consistent with themselves, they are out of reach of rational conviction, nor do they deserve a rational argument.

Logic is the art of convincing us some truth.

Induction for deduction, with a view to construction.

It is not really difficult to construct a series of inferences, each dependent upon its predecessor and each simple in itself. If, after doing so, one simply knocks out all the central inferences and presents one's audience with the starting-point and the conclusion, one may produce a startling, though perhaps a meretricious, effect.

To me it is unthinkable that a real atheist could be a scientist.

Unless thought is valid we have no reason to believe in the real universe.

Stripping away the irrational, the illogical, and the impossible, I am left with atheism. I can live with that.

Deduction, which takes us from the general proposition to facts again-teaches us, if I may so say, to anticipate from the ticket what is inside the bundle.

This method of deduction ... is often called "combinatory". Its usefulness is not exhausted at this stage, but it does even at the outset lead to some valuable conclusions.

An agnostic is a cowardly atheist.