Theognis (540 BC - 480 BC / Greece)

My heart, display toward all your friends a changeful character,
Adding into it the disposition that each one has.
Adopt the disposition of the octopus, crafty in its convolutions, which takes on
The appearance of whatever rock it has dealings with.
At one moment follow along this way, but at the next change the color of your skin:
You can be sure that cleverness proves better than inflexibility.