Myths of Greece and Rome, by Jane Harrison, [1928], at sacred-texts.com
As to the primary origin and significance of Zeus there is happily no doubt. He is the Indo-European sky-god in its two aspects; he is the god of the Bright Sky and the shining ether, and also of the Dark Sky, the god of thunder and rain. When the gods drew lots for shares in the universe Poseidon, Homer tells us, drew the sea, Hades the murky darkness, and Zeus "the wide heaven." The most primitive figures in Greek theology, long before Homer, were Ouranos and Gaia, Heaven and Earth; and of Ouranos Zeus had preserved many characteristics. Accordingly, in Homer's pantheon, Zeus, before all things, is the Loud-Thunderer, the Cloud-Gatherer; "he lighteneth, fashioning either a rain unspeakable or hail or snow, when the flakes sprinkle the ploughed lands." He has for his messenger Iris the Rainbow.
These traits, appropriate to the elemental sky-god, are a little difficult to fit in with the moral characteristics of the model father, husband, and ruler, and assuredly the human Zeus of Homer cannot command our admiration. He is apt, as we have seen, to behave like the uncontrolled
thunderstorm he once was. He explodes automatically at the smallest opposition. Moreover, he is shamelessly licentious, he bullies and maltreats his wife. Yet there are beginnings of better things. He has his kindly aspect as god of strangers, beggars, and suppliants generally.
For his complete moralization the figure of Zeus had to await the genius of Æschylus. To Æschylus Zeus was at once the mysterious power that moves the universe and the moral solution of all-world problems. He cries: "Zeus, our Unknown, whom, since so to be called is his pleasure, I so address. When I ponder upon all things I can conjecture naught but Zeus to fit the need, if the burden of vanity is in very truth to be cast from the soul." And again: "Never, never shall mortal counsels overpass the harmony of Zeus." This is, indeed, a far cry from the elemental thunderstorm.
It is not, however, only the genius of Æschylus that has enlarged, softened, and beautified the conception of Zeus, till his elemental form is almost wholly lost. Pheidias, in the great chryselephantine statue of Zeus at Olympia, embodied the ideas of the time of Æschylus, and Quintilian, in discussing this image, makes this notable statement: "Its beauty seems to have added something to revealed religion." Dio Chrysostom wrote as follows:
"Our Zeus is peaceful and altogether mild, as the guardian of Hellas when she is of one mind and not distraught with faction, an image gentle and august in perfect form, one who is the giver of life and breath and every good gift, the common father and saviour and guardian of mankind. The image brought to the troubled heart of the beholder something of its own large repose. 'If there be any of mortals whatsoever that is heavy laden in spirit, having suffered sorely many sorrows and calamities in his life, nor yet winning for himself sweet sleep, even such an one, methinks, standing
before the image of the god, would forget all things whatsoever in his mortal life hard to be endured, so wondrously hast thou Pheidias, conceived and wrought it, and such grace and light shine upon it from thy art.'"
Such is the life history of Zeus from thunderstorm to Paraclete.