Truth is the recognition of reality; reason, man's only means of knowledge, is his only standard of truth.
It is time, therefore, to abandon the superstition that natural science cannot be regarded as logically respectable until philosophers have solved the problem of induction. The problem of induction is, roughly speaking, the problem of finding a way to prove that certain empirical generalizations which are derived from past experience will hold good also in the future.
one of the tests of a theory is that, once grasped, it appears self-evident.
Is there any knowledge in the world which is so certain that no reasonable man could doubt it?
We must consider both the ultimate end and all clear sensory evidence, to which we refer our opinions; for otherwise everything will be full of uncertainty and confusion.
We do not respect people's beliefs, we evaluate their reasons. If my reasons are good enough for believing what I believe, you will helplessly believe what I believe. I will give you my reasons and reasons are contagious. That is what it is to be a rational human being.
It is therefore worthwhile, to search out the bounds between opinion and knowledge; and examine by what measures, in things, whereof we have no certain knowledge, we ought to regulate our assent, and moderate our persuasions.
In the end, every scheme and every science is justified by itself or it is not justified at all.
Even by proving that a certain view is indispensable for living well, one proves merely that the view in question is a salutary myth: one does not prove it to be true.
Knowledge, or more expressively truth,--for knowledge is truth received into our intelligence,--truth is an ideal whole.
If an opinion can eventually go to the determination of a practical belief, it, in so far, becomes itself a practical belief; and every proposition that is not pure metaphysical jargon and chatter must have some possible bearing upon practice.
We cannot ultimately specify the grounds (either metaphysical or logical or empirical) upon which we hold that our knowledge is true. Being committed to such grounds, dwelling in them, we are projecting ourselves to what we believe to be true from or through these grounds. We cannot therefore see what they are. We cannot look at them because we are looking with them.
As soon as it is held that any belief, no matter what, is important for some other reason than that it is true, a whole host of evils is ready to spring up.
The truth of a proposition has nothing to do with its credibility. And vice versa.