Karl Popper

"I think there is virtue in the admission of uncertainty."

"The pursuit of knowledge is the pursuit of truth."

"In politics, the greatest danger is perhaps that of over-confidence in one's own wisdom."

"We must not preach a doctrine of despair; we must preach a doctrine of human dignity and responsibility."

"Every scientific statement must remain tentative for ever."

"The source of our mistakes is not the limitation of our knowledge, but the pretense of it."

"Beauty in art is the expression of truth."

"We cannot live without myths, but we can live critically with them."

"The task is not so much to see what no one has yet seen, but to think what nobody has yet thought about that which everybody sees."

"A living world is growing and changing constantly."

"The greatest threat to freedom is the absence of criticism."

"We must adjust our expectations to the actual possibilities."

"Knowledge without criticism is blind acceptance."

"History is not a science, but it can teach us through its patterns."

"The best argument against democracy is a five-minute conversation with the average voter. Yet it remains the least bad option."

"Fear of the unknown is the source of human wisdom."

"We learn by making mistakes and by the criticism of our mistakes."

"The need for intellectual honesty is paramount in the pursuit of truth."

"In science, there are no final answers, only better questions."

"Work is not something to escape, but something through which to express our nature."

"The ability to imagine the future gives us hope for change."

"We must be bold in our ideas but careful in our conclusions."

"Justice requires the willingness to listen to all sides."

"The contemplative life has value, but so does the active one."

"Patience is not passive; it is the active process of learning."

"Kindness is the expression of our recognition of shared humanity."

"True strength lies in the admission of weakness."

"Money is a tool, not an end in itself."

"Health is the foundation upon which all other goods rest."

"Adventure is the willingness to embrace the unknown."