Laudator Temporis Acti

Jonathan Bate, The Song of the Earth (Cambridge: Harvard University Press, 2000), pp. 26-27:

The earliest surviving version of this ancient Greek myth of origins is the Theogony of Hesiod. It tells of how the original Golden Age declined to Silver and thence to Bronze and finally to the Iron of the present.

Bate is correct in naming Hesiod, but it is in the Works and Days (lines 106-201), not in the Theogony, that Hesiod relates the myth of origins and the ages of men. The Iron Age (Works and Days 182-201, tr. Hugh G. Evelyn-White) is no myth but reality:

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 dishonour 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 their nurture, for might shall be their right: and one man will sack another's city. There will be no favour for the man who keeps his oath or for the just or for the good; but rather men will praise the evil-doer and his violent dealing. Strength will be right and reverence will cease to be; and the wicked will hurt the worthy man, speaking false words against him, and will swear an oath upon them. Envy, foul-mouthed, delighting in evil, with scowling face, will go along with wretched men one and all. And then Aidôs and Nemesis, with their sweet forms wrapped in white robes, will go from the wide-pathed earth and forsake mankind to join the company of the deathless gods: and bitter sorrows will be left for mortal men, and there will be no help against evil.