Protagoras (c.485-410 BCE)
Man is the measure of all things.
Socrates (c.470-399 BCE)
The unexamined life is not worth living.
Plato (c.428-c.348 BCE)
A good decision is based on knowledge and not on numbers
Opinion is the medium between knowledge and ignorance.
Aristotle (384-322 BCE)
Happiness is something final and complete in itself, as being the aim and end of all practical activities whatever … Happiness then we define as the active exercise of the mind in conformity with perfect goodness or virtue.“
Doubt transports you to the truth. Who does not doubt fails to inquire. Who does not inquire fails to gain insight. Without insight, you remain blind and perplexed
Thomas Aquinas (c.1224-1274)
Now laws are said to be just both from the end (when, namely, they are ordained to the common good), from their author (… when the law does not exceed the power of the lawgiver), and from their form (when, namely, burdens are laid on the subjects according to an equality of proportion).
Ibn Khaldun (1332-1406)
Not everyone is master of his own affairs … As a rule, man must by necessity be dominated by someone else. If the domination is kind and just and the people under it are not oppressed by its law and restrictions, they are guided by the courage or cowardice that they possess in themselves …
René Descartes (1596-1650)
There is a great difference between mind and body, inasmuch as body is by nature always divisible, and the mind is entirely indivisible.
Thomas Hobbes (1588-1679)
True and false are attributes of speech, not of things. And where speech is not there is neither Truth nor Falsehood.
Benedict Spinoza (1632-1677)
Love is pleasure accompanied by the idea of an external cause, and hatred pain accompanied by the idea of an external cause.
I have striven not to laugh at human actions, not to weep at them, nor to hate them, but to understand them
David Hume (1711-1776)
The effect is totally different from the cause, and consequently can never be discovered in it.
George Berkeley (1685-1753)
The very notion of what is called Matter or corporeal substance involves a contradiction.
Jean-Jacques Rousseau (1712-1778)
Man was born free, and everywhere he is in chains.
Immanuel Kant (1724-1804)
The understanding does not derive its laws (a priori) from, but prescribes them to, nature.
There is … only a single categorical imperative and it is this: Act only on that maxim through which you can at the same time will that it should become a universal law!
Mary Wollstonecraft (1759-1797)
The two sexes mutually corrupt and improve each other.
John Stuart Mill (1806-1873)
The only purpose for which power can be rightfully exercised over any member of a civilized community, against his will, is to prevent harm to others.
Friedrich Nietzsche (1844-1900)
Almost every party grasps that it is in the interest of its own self-preservation that the opposing party should not decay in strength; the same is true of grand politics. A new creation, the new Reich for instance, has more need of enemies that friends: only in opposition does it feel itself necessary, only in opposition does it become necessary….
William James (1842-1910)
There can be no difference anywhere that does not make a difference somewhere.
Ludwig Wittgenstein (1889-1951)
Whereof one cannot speak thereof one must be silent.
J. L. Austin (1911-1960)
Fact is richer than diction.
Jean-Paul Sartre (1905-1980)
Existence precedes essence.