Diogenes

Those who have virtue always in their mouths, and neglect it in practice, are like a harp, which emits a sound pleasing to others, while itself is insensible of the music.
Those who have virtue always in their mouths, and neglect it in practice, are like a harp, which emits a sound pleasing to others, while itself is insensible of the music.
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These are some quotes by Greek author Diogenes Philosopher, who lived between 412 BC and 323 BC.