Some of the people who have “changed the world” have been so inspirational and influential on human thought and humankind’s progress that many actively seek their nuggets of wisdom via powerful quotes. In fact, their quotations alone have been enough to inspire others to change their lives for the better. From Socrates and Aristotle to Albert Einstein and Carl Sagan, these are 25 Powerful Quotes From Scientists That Are Truly Thought-Provoking.