Popper, Karl

"The irony of life is that our greatest strengths are often our greatest weaknesses."

"We cannot prove anything absolutely; we can only choose which errors to risk making."

"The future belongs to those willing to question the present."

"Kindness is not weakness; it is the strength to see others as equal in worth."

"We solve problems by breaking them into smaller problems, not by seeking grand solutions."

"The most dangerous dogma is the belief that we have finally achieved complete knowledge."

"Time reveals what thinking cannot; therefore we must act despite our uncertainty."

"The open society depends on people willing to openly disagree without hatred."

"The growth of knowledge is the growth of the awareness of our ignorance."

"We must learn not to be ashamed of our mistakes. It is the only way to learn."

"Science may be described as the art of systematic over-simplification."

"The attempt to make heaven on earth produces hell."

"Our knowledge is a drop, but our ignorance is an ocean."

"I have always grown from my problems and challenges, rather than from successes."

"The beginning of wisdom is the definition of terms."

"We are not interested in the possibilities of defeat; they do not exist."

"Against relativism, one must insist that there is a reality independent of any human beliefs."

"It is impossible to speak in such a way that you cannot be misunderstood."

"What appears to the mind of man as beauty is the universal language through which he communicates with truth."

"The paradox is only a conflict between reality and your feeling of what reality ought to be."

"All life is problem solving."

"Expectations often determine experiences, but there is always a reality that can invalidate them."

"Democracy rests on the principle that power must be limited."

"The more we learn about the world, the more we recognize its inexhaustibility."

"Suffering is endemic to life; it is not a sign that something has gone wrong."

"Every discovery contains an irrational element, a creative intuition."

"Freedom of thought is in danger of disappearing not because of any frontal attack."

"We should therefore claim, in the name of tolerance, the right not to tolerate the intolerant."

"There is no such thing as a logically closed totality in science."

"Theories are nets cast to catch the world; only the ones that actually catch something are worth keeping."