Leon Lederman

"Mistakes are the portals of discovery."

"The universe operates on probability, not certainty."

"Energy and persistence conquer all things."

"Tell me and I forget, teach me and I may remember, involve me and I learn."

"The arc of history bends toward justice, but it does not bend on its own."

"Between stimulus and response there is a space. In that space is our power to choose."

"The greatest discovery of science is that we know so little."

"A question that makes you think is far more valuable than an answer."

"The mind of the universe is mathematical."

"If you love what you do, you'll never work a day in your life."

"The human spirit is stronger than anything that can happen to it."

"Peace comes from within. Do not seek it without."

"Everything you want is on the other side of fear."

"The only constant in life is change itself."

"Gratitude is the most powerful emotion because it shifts perspective."

"A mind is like a parachute; it only works when it's open."

"The universe is fundamentally creative."

"Doubt is the birthplace of all discovery."

"Life is not about finding yourself; it's about creating yourself."

"The purpose of life is a life of purpose."

"What we do for ourselves dies with us; what we do for others is eternal."

"The best way to predict the future is to invent it."

"Patience is not passive; it is concentrated strength."

"The laws of nature are written in the language of mathematics."

"Failure is just another name for the data we haven't understood yet."

"Life's tragedy is that we get old too soon and wise too late."

"The only real security is knowing you can handle whatever comes."

"Curiosity is the most human of all our traits."

"The universe rewards those who maintain enthusiasm and wonder."

"What lies behind us and what lies before us are tiny matters compared to what lies within us."