Do not believe in anything simply because you have heard it. Do not believe in anything simply because it is spoken and rumored by many. Do not believe in anything simply because it is found written in your religious books. Do not believe in anything merely on the authority of your teachers and elders. But after observation and analysis, when you find that anything agrees with reason and is conducive to the good and benefit of one and all, then accept it and live up to it.
Rationality
The systematic pursuit of truth through reason, evidence, and coherent thinking
Reason is the natural order of truth; but imagination is the organ of meaning.
The essence of the independent mind lies not in what it thinks, but in how it thinks.
Clear thinking requires courage rather than intelligence.
A rational mind never fits comfortably into an irrational world.
It is not enough to have a good mind; the main thing is to use it well.
The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge.
Reason is the slave of the passions, not their master. True rationality means understanding this relationship.
Rationality is the recognition that facts don't care about your feelings, but that feelings are facts that must be accounted for in any complete system of reasoning.
The first principle is that you must not fool yourself - and you are the easiest person to fool.
A man is rational, not when he has the right answers, but when he asks the right questions.
Logic takes care of itself; all we have to do is to look and see how it does it.
Rationality is not about having no emotions; it's about not letting your emotions have you.
The whole problem with the world is that fools and fanatics are always so certain of themselves, and wiser people so full of doubts.
Reason is the greatest enemy that faith has; it never comes to the aid of spiritual things, but - more frequently than not - struggles against the divine Word.
To be rational is not to be emotionless, but to ensure that your emotions serve your values rather than override them.
The rational person accepts that they are irrational in predictable ways, and builds systems to compensate.
Truth does not become more true by virtue of the fact that the entire world agrees with it, nor less so even if the whole world disagrees with it.
Rationality requires the humility to change your mind when evidence demands it, and the courage to hold your ground when it doesn't.
The map is not the territory, but a good map gets you where you want to go. Rationality is the art of map-making.
He who will not reason is a bigot; he who cannot is a fool; and he who dares not is a slave.
Rationality is not about being cold and calculating; it's about being effective at achieving what you actually want.
The test of a first-rate intelligence is the ability to hold two opposed ideas in mind at the same time and still retain the ability to function.
Reason is the natural light that enables us to see the truth, but we must have the courage to look where it shines.
A rational argument doesn't necessarily persuade anyone, but it does separate those who can think from those who merely feel.