Which famous historical figure said "Knowing yourself is the beginning of all wisdom."?

Aristotle's quote means when people take the time to unlock their inner world, then outer experiences makes more sense.

Aristotle (c. 384 B.C. to 322 B.C.) was an Ancient Greek philosopher and scientist who is still considered one of the greatest thinkers in politics, psychology and ethics. When Aristotle turned 17, he enrolled in Plato’s Academy. In 338 B.C., he began tutoring Alexander the Great. In 335 B.C., Aristotle founded his own school, the Lyceum, in Athens, where he spent most of the rest of his life studying, teaching and writing.

When Alexander the Great died suddenly in 323 B.C., the pro-Macedonian government was overthrown, and in light of anti-Macedonia sentiment, Aristotle was charged with impiety for his association with his former student and the Macedonian court. To avoid being prosecuted and executed, he left Athens and fled to Chalcis on the island of Euboea. Just a year after he fled he contracted a disease of the digestive organs and died in 322 B.C.

Aristotle wrote an estimated 200 works, most in the form of notes and manuscript drafts touching on reasoning, rhetoric, politics, ethics, science and psychology. They consist of dialogues, records of scientific observations and systematic works.