Hesiod said this quote

That man is best who sees the truth himself. Good too is he who listens to wise counsel. But who is neither wise himself nor willing to ponder wisdom is not worth a straw.

~ Hesiod

…Perses, hear me out on justice, and take what I have to say to heart; cease thinking of violence. For the son of Kronos, Zeus, has ordained this law to men: that fishes and wild beasts and winged birds should devour one another, since there is no justice in them; but to mankind he gave justice which proves for the best.

~ Hesiod

He's only harming himself who's bent upon harming another

~ Hesiod

Never wade through the pretty ripples of perpetually flowing rivers, until you have looked at their lovely waters,and prayed to them,and washed your hands in the pale enchanting water.

~ Hesiod