"An optimist is a person who sees a green light everywhere. The pessimist sees only the red light. But the truly wise person is color blind" ...who said so?

Albert Schweitzer is known for this philosophical quote contrasting optimism, pessimism, and wisdom. The quote uses the metaphor of traffic lights to describe different outlooks on life - optimists see opportunities (green lights), pessimists see obstacles (red lights), while the wise person remains balanced and impartial (color blind). This reflects Schweitzer's philosophical perspective on maintaining a balanced worldview.