"The sexual life of adult women is a "dark continent" for psychology." ~ Sigmund Freud

"A fool is known by his speech; and a wise man by silence." ~ Pythagoras

"Be a free thinker and don't accept everything you hear as truth. Be critical and evaluate what you believe in." ~ Aristotle

"Awareness of ignorance is the beginning of wisdom." ~ Socrates

"Doubt is the origin of wisdom" ~ Rene Descartes

"Whoever fights monsters should see to it that in the process he does not become a monster. And if you gaze long enough into an abyss, the abyss will gaze back into you." ~ Friedrich Nietzsche

"He who hasn't tasted bitter things hasn't earned sweet things." ~ Gottfried Leibniz

"What worries you, masters you." ~ John Locke

"Nothing in nature is by chance... Something appears to be chance only because of our lack of knowledge." ~ Baruch Spinoza

"Always recognize that human individuals are ends, and do not use them as means to your end." ~ Immanuel Kant

"If you are lonely when you're alone, you are in bad company." ~ Jean-Paul Sartre

"The only shame in masturbation is the shame of not doing it well." ~ Sigmund Freud

"No man has any natural authority over his fellow men." ~ Jean-Jacques Rousseau