"The tendency to aggression is an innate, independent, instinctual disposition in man... it constitutes the most powerful obstacle to culture."

"No one who has tasted the forbidden fruit of knowledge can ever again be satisfied with the primitive bliss of ignorance."

"The great question that has never been answered, and which I myself have not yet been able to answer, despite my thirty years of research into the feminine soul, is 'What does a woman want?'"

"The libido is the energy, regarded as a quantitative magnitude, of those instincts which have to do with all that may be comprised under the word 'love.'"

"The ego represents what may be called reason and common sense, in contrast to the id, which contains the passions."