“The unexamined life is not worth living” – Socrates “Whereof one cannot speak, thereof one must be silent” – Ludwig Wittgenstein “Entities should not be multiplied unnecessarily” – William of Ockham “The life of man (in a state of nature) is solitary, poor, nasty, brutish, and short” – Thomas Hobbes “I think therefore I am” (“Cogito, ergo sum”) – René Descartes “He who thinks great thoughts, often makes great errors” – Martin Heidegger “We live in the best of all possible worlds” – Gottfried Wilhelm Leibniz “What is rational is actual and what is actual is rational” – G. W. F. Hegel “God is dead! He remains dead! And we have killed him.” – Friedrich Nietzsche “There is but one truly serious philosophical problem, and that is suicide” – Albert Camus “One cannot step twice in the same river” – Heraclitus “The greatest happiness of the greatest number is the foundation of morals and legislation” – Jeremy Bentham “To be is to be perceived” (“Esse est percipi”)– Bishop George Berkeley “Happiness is not an ideal of reason but of imagination” – Immanuel Kant “No man's knowledge here can go beyond his experience” – John Locke “God is not willing to do everything, and thus take away our free will and that share of glory which belongs to us” – Niccolo Machiavelli “Liberty consists in doing what one desires” – John Stuart Mill “It is undesirable to believe a proposition when there is no ground whatever for supposing it true” – Bertrand Russell “There is only one good, knowledge, and one evil, ignorance” – Socrates “If God did not exist, it would be necessary to invent Him” – Voltaire “This is patently absurd; but whoever wishes to become a philosopher must learn not to be frightened by absurdities” – Bertrand Russell “One cannot conceive anything so strange and so implausible that it has not already been said by one philosopher or another” – René Descartes “Leisure is the mother of philosophy” – Thomas Hobbes “Philosophy is a battle against the bewitchment of our intelligence by means of language” – Ludwig Wittgenstein “There is only one thing a philosopher can be relied upon to do, and that is to contradict other philosophers” – William James “We are what we repeatedly do. Excellence, then, is not an act, but a habit” – Aristotle “Only one man ever understood me, and he didn’t understand me” – G. W. F. Hegel “The mind is furnished with ideas by experience alone” – John Locke “Life must be understood backward. But it must be lived forward ” – Søren Kierkegaard “Science is what you know. Philosophy is what you don't know” – Bertrand Russell “Metaphysics is a dark ocean without shores or lighthouse, strewn with many a philosophic wreck” – Immanuel Kant “Philosophy is at once the most sublime and the most trivial of human pursuits” – William James “History is Philosophy teaching by examples” – Thucydides “He who is unable to live in society, or who has no need because he is sufficient for himself, must be either a beast or a god” – Aristotle “You can discover more about a person in an hour of play than in a year of conversation” – Plato “Things alter for the worse spontaneously, if they be not altered for the better designedly” – Francis Bacon “All that is necessary for the triumph of evil is that good men do nothing” – mistakenly attributed to Edmund Burke “Is man merely a mistake of God'n? Or God merely a mistake of man's?” – Friedrich Nietzsche “I would never die for my beliefs because I might be wrong” – Bertrand Russell “Religion is the sign of the oppressed ... it is the opium of the people” – Karl Marx “Happiness is the highest good” – Aristotle “If men were born free, they would, so long as they remained free, form no conception of good and evil” – Baruch Spinoza “The greater the difficulty, the more glory in surmounting it” – Epicurus “Whatever is reasonable is true, and whatever is true is reasonable” – G. W. F. Hegel “Morality is not the doctrine of how we may make ourselves happy, but of how we may make ourselves worthy of happiness” – Immanuel Kant “Man is condemned to be free” – Jean-Paul Sartre “It is one thing to show a man that he is in error, and another to put him in possession of truth” – John Locke “I don’t know why we are here, but I’m pretty sure it is not in order to enjoy ourselves” – Ludwig Wittgenstein “That man is wisest who, like Socrates, realizes that his wisdom is worthless” – Plato “The only thing I know is that I know nothing” – Socrates “All is for the best in the best of all possible worlds” – Voltaire (in parody of Leibniz) “The function of prayer is not to influence God, but rather to change the nature of the one who prays” – Søren Kierkegaard “Man is born free, but is everywhere in chains” – Jean-Jacques Rousseau “Man will never be free until the last king is strangled with the entrails of the last priest” – Denis Diderot “If you would be a real seeker after truth, it is necessary that at least once in your life you doubt, as far as possible, all things” – René Descartes “Happiness lies in virtuous activity, and perfect happiness lies in the best activity, which is contemplative” – Aristotle “I can control my passions and emotions if I can understand their nature” – Spinoza “Philosophers have hitherto only interpreted the world in various ways; the point, however, is to change it” – Karl Marx “It is wrong always, everywhere and for everyone, to believe anything upon insufficient evidence” – W. K. Clifford “Virtue is nothing else than right reason” – Seneca the Younger “Freedom is secured not by the fulfilling of one's desires, but by the removal of desire” – Epictetus “In everything, there is a share of everything” – Anaxagoras “A little philosophy inclineth man's mind to atheism; but depth in philosophy bringeth men’s minds about to religion” – Sir Francis Bacon “The brave man is he who overcomes not only his enemies but his pleasures” – Democritus “Good and evil, reward and punishment, are the only motives to a rational creature” – John Locke “To do as one would be done by, and to love one's neighbor as oneself, constitute the ideal perfection of utilitarian morality” – John Stuart Mill “Everything that exists is born for no reason, carries on living through weakness, and dies by accident” – Jean-Paul Sartre “Man is the measure of all things” – Protagoras “We are too weak to discover the truth by reason alone” – St. Augustine “The mind is furnished with ideas by experience alone” – John Locke "Luck is what happens, when preparation meets opurtunity" - Seneca