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• When Thales was asked what was difficult, he said, "To know one's self.
  And what was easy, "To advise another." -- Diogenes Laertius (c. 200 AD) -- Thales, ix...
• He said that men ought to remember those friends who were absent as well as those who were present.
  -- Diogenes Laertius (c. 200 AD) -- Thales, ix...
• Very late in life, when he was studying geometry, some one said to Lacydes, "Is it then a time for you to be learning now?
  If it is not," he replied, "when will it be?" -- Diogenes Laertius (c. 200 AD) -- Lacydes, v...
• Bury me on my face," said Diogenes; and when he was asked why, he replied, "Because in a little while everything will be turned upside down.
  -- Diogenes Laertius (c. 200 AD) -- Diogenes, vi...
• Writers differ with respect to the apophthegms of the Seven Sages, attributing the same one to various authors.
  -- Diogenes Laertius (c. 200 AD) -- Thales, xiv...
• The apophthegm "Know thyself" is his. -- Diogenes Laertius (c. 200 AD) -- Thales, xiii
• Of a rich man who was niggardly he said, "That man does not own his estate, but his estate owns him.
  -- Diogenes Laertius (c. 200 AD) -- Bion, iii...
• He said that there was one only good, namely, knowledge
  and one only evil, namely, ignorance. -- Diogenes Laertius (c. 200 AD) -- Socrates, xiv...
• When asked what learning was the most necessary, he said, "Not to unlearn what you have learned.
  -- Diogenes Laertius (c. 200 AD) -- Antisthenes, iv...