It was a saying of Hippocrates that the number seven, by reason of its mystic virtues, tended to the accomplishment of all things, and was the dispenser of life and the fountain of all its changes; for as the moon changes its phases every seven days, so this number influences all sublunary beings.[521] The phrase “to be in the seventh heaven” was derived from the seven planets, which were believed by the Babylonians to be carried around upon as many globes of crystal, the seventh being the highest.[522] In the writings of the Cabalists of old are likewise portrayed seven heavens, one above another, and the seventh or highest was the abode of God and the higher angels. The ultimate source of the sanctity of the number seven has, however, been ascribed to the septentriones, the seven ploughing oxen, stars of the constellation of the Great Bear.
An ingenious but not especially plausible reason alleged for the popularity of this number is the fact of its being composed of three, the number of sides in a triangle, and four, the number of sides in a square, thus representing two of the simplest geometric figures.[523]
Certain Biblical critics of a speculative turn of mind have concluded that its prominence as a symbol is due to the emblematic significance of its component parts, three and four; the former representing Divinity, and the latter Humanity: in other words, “the union between God and man, as affected by the manifestations of the Divinity in creation and revelation.”[524]
In some portions of a great work on magic, discovered by Mr. A. H. Layard among fragments of clay tablets in the ruins of a palace in ancient Nineveh, are many incantations, formulæ, and conjurations, in which the number seven occurs repeatedly.[525]
As familiar instances of the prominence of this number in former times may be cited the seven wise men of Greece, the seven gates of Thebes, and the legend of the seven sleepers of Ephesus.
Other examples are given in the following “seven heroic verses” sent by a certain Mr. Michelburn to one Mr. Crisp, who owed the former seven shillings:—
Friend Crisp, I send you verses only sev’n,
The number’s od, God numbers lovs unev’n;
Sev’n Hills at Rome, sev’n mouths of Nilus are,