Reason and passion

“Reason is, and ought only to be the slave of the passions, and can never pretend to any other office than to serve and obey them.”

— David Hume, A Treatise of Human Nature

“Sapere aude! Dare to know! Have courage to use your own understanding!”

— Kant, Beantwortung der Frage Was ist Aufklärung

“I think, therefore I am.”

— Descartes, Discours de la méthode

“Let him look upon reason as a monarch sitting on the throne of his heart.”

— Al-Ghazali, Some religious and moral teachings of Al-Ghazzali Being brief extracts from his

“Truth is omnipotent.”

— William Godwin, Thoughts on Man, His Nature, Productions, and Discoveries

“The heart has its reasons, which reason does not know.”

— Pascal, Pascal's Pensées

“A wise man proportions his belief to the evidence.”

— David Hume, An Enquiry Concerning Human Understanding

“People who know little are usually great talkers, while men who know much say little.”

— Rousseau, Emile

“Reading maketh a full man; conference a ready man; and writing an exact man.”

— Francis Bacon, Bacon's Essays, and Wisdom of the Ancients

“Some books are to be tasted, others to be swallowed, and some few to be chewed and digested.”

— Francis Bacon, Bacon's Essays, and Wisdom of the Ancients

“Their esse is percipi — "their being is to be perceived."”

— George Berkeley, A Treatise Concerning the Principles of Human Knowledge

“The mind is not a vessel which calls for filling. It is a pile, which simply requires kindling-wood to start the flame of eagerness for original thought.”

— Plutarch, Selected Essays of Plutarch, Vol. I.

“White paper receives any characters.”

— Locke, An Essay Concerning Humane Understanding, Volume 1

“Not to know what happened before one was born, is to be a boy all one's life.”

— Cicero, The Orations of Marcus Tullius Cicero, Volume 4

“Two things fill the mind with ever new and increasing admiration and awe: the starry heavens above and the moral law within.”

— Kant, Critique of Practical Reason

“When you know a thing, to hold that you know it; and when you do not know a thing, to allow that you do not know it — this is knowledge.”

— Confucius, The Analects of Confucius (from the Chinese Classics)

“A being than which nothing greater can be conceived.”

— Anselm of Canterbury, Proslogium, Monologium, and Cur Deus Homo (Deane)

“The liberty of man consists solely in this: that he obeys natural laws because he has himself recognized them as such.”

— Mikhail Bakunin, God and the State

“A foolish consistency is the hobgoblin of little minds.”

— Ralph Waldo Emerson, Essays — First Series

“Good sense is, of all things among men, the most equally distributed.”

— Descartes, Discourse on the Method of Rightly Conducting One's Reason and of Seeking Truth

“A firm conviction of the mind to the effect that Brahman is real and the universe unreal, is designated as discrimination between the Real and the unreal.”

— Adi Shankara, Vivekachudamani

“The truth of an idea is not a stagnant property inherent in it. Truth happens to an idea. It becomes true, is made true by events.”

— William James, Pragmatism A New Name for Some Old Ways of Thinking

“Convictions are more dangerous enemies of truth than lies.”

— Nietzsche, Human, All-Too-Human A Book for Free Spirits, Part 1

“Every man takes the limits of his own field of vision for the limits of the world.”

— Arthur Schopenhauer, The Essays of Arthur Schopenhauer; Studies in Pessimism

“The years teach much which the days never know.”

— Ralph Waldo Emerson, Essays — Second Series

“The more we understand particular things, the more do we understand God.”

— Spinoza, Ethics

“All the choir of heaven and furniture of the earth... have not any subsistence without a mind.”

— George Berkeley, A Treatise Concerning the Principles of Human Knowledge

“Philosophy begins in wonder.”

— Plato, Theaetetus

“Generally speaking, the errors in religion are dangerous; those in philosophy only ridiculous.”

— David Hume, A Treatise of Human Nature

“Obstinacy is the result of the will forcing itself into the place of the intellect.”

— Arthur Schopenhauer, The Essays of Arthur Schopenhauer; Religion, a Dialogue, Etc.

“The world is but a school of inquisition: it is not who shall enter the ring, but who shall run the best courses.”

— Michel de Montaigne, Essays of Michel de Montaigne — Complete

“Who can make the muddy water clear? Let it be still, and it will gradually become clear.”

— Laozi, The Tao Teh King, or the Tao and its Characteristics

“The eternal silence of these infinite spaces frightens me.”

— Pascal, Pascal's Pensées

“The Universe is either a confusion ravelled and unravelled again, or else a unity compact of order and forethought.”

— Marcus Aurelius, The Meditations of the Emperor Marcus Aurelius Antoninus

“Astronomy compels the soul to look upwards and leads us from this world to another.”

— Plato, The Republic

“Knowledge which is acquired under compulsion obtains no hold on the mind.”

— Plato, The Republic