Diogenes the Cynic was a Greek philosopher who lived from about 404 B.C. to 323 B.C. He was a slave in his youth. He practiced asceticism, choosing to live without luxuries and begging for his food. Diogenes believed that everything a person needs to be happy can be found within himself/herself ("Diogenes", 2016).
Diogenes. (2016). In Encyclopædia Britannica. Retrieved from http://www.britannica.com/biography/Diogenes-Greek-philosopher