Hesiod

Muses of Pieria who give glory through song, come hither, tell of Zeus your father and chant his praise. Through him mortal men are famed or unfamed, sung or unsung alike, as great Zeus wills.
For easily he makes strong, and easily he brings the strong man low; easily he humbles the proud and raises the obscure, and easily he straightens the crooked and blasts the proud,—Zeus who thunders aloft and has his dwelling most high.

So, after all, there was not one kind of Strife alone, but all over the earth there are two. As for the one, a man would praise her when he came to understand her; but the other is blameworthy: and they are wholly different in nature. For one fosters evil war and battle, being cruel:
her no man loves; but perforce, through the will of the deathless gods, men pay harsh Strife her honor due. But the other is the elder daughter of dark Night, and the son of Cronos who sits above and dwells in the aether, set her in the roots of the earth: and she is far kinder to men.
She stirs up even the shiftless to toil; for a man grows eager to work when he considers his neighbor, a rich man who hastens to plough and plant and put his house in good order; and neighbor vies with his neighbor as he hurries after wealth. This Strife is wholesome for men.

And potter is angry with potter, and craftsman with craftsman, and beggar is jealous of beggar, and minstrel of minstrel.

Little concern has he with quarrels and courts who has not a year's victuals laid up betimes, even that which the earth bears, Demeter's grain. When you have got plenty of that, you can raise disputes and strive to get another's goods.

For we had already divided our inheritance, but you seized the greater share and carried it off, greatly swelling the glory of our bribe-swallowing lords who love to judge such a cause as this.
Fools! They know not how much more the half is than the whole, nor what great advantage there is in mallow and asphodel.

For the gods keep hidden from men the means of life. Else you would easily do work enough in a day to supply you for a full year even without working;
soon would you put away your rudder over the smoke, and the fields worked by ox and sturdy mule would run to waste.

Thereafter, would that I were not among the men of the fifth generation,
but either had died before or been born afterwards. For now truly is a race of iron, and men never rest from labor and sorrow by day, and from perishing by night; and the gods shall lay sore trouble upon them. But, notwithstanding, even these shall have some good mingled with their evils.

The father will not agree with his children, nor the children with their father, nor guest with his host, nor comrade with comrade; nor will brother be dear to brother as aforetime.
Men will dishonor their parents as they grow quickly old, and will carp at them, chiding them with bitter words, hard-hearted they, not knowing the fear of the gods. They will not repay their aged parents the cost of their nurture, for might shall be their right: and one man will sack another's city.

But you, Perses, listen to right and do not foster violence; for violence is bad for a poor man.
Even the prosperous cannot easily bear its burden, but is weighed down under it when he has fallen into delusion. The better path is to go by on the other side towards Justice; for Justice beats Outrage when she comes at length to the end of the race. But only when he has suffered does the fool learn this.

But they who give straight judgements to strangers and to the men of the land, and go not aside from what is just, their city flourishes, and the people prosper in it: Peace, the nurse of children, is abroad in their land, and all-seeing Zeus never decrees cruel war against them.
Neither famine nor disaster ever haunt men who do true justice; but light-heartedly they tend the fields which are all their care.