medieval science. The sacred power of the number three was seen in the
Trinity; in the three main divisions of the universe--the empyrean, the
heavens, and the earth; in the three angelic hierarchies; in the three
choirs of seraphim, cherubim, and thrones; in the three of dominions,
virtues, and powers; in the three of principalities, archangels,
and angels; in the three orders in the Church--bishops, priests, and
deacons; in the three classes--the baptized, the communicants, and the
monks; in the three degrees of attainment--light, purity, and knowledge;
in the three theological virtues--faith, hope, and charity--and in much
else. All this was brought into a theologico-scientific relation,
then and afterward, with the three dimensions of space; with the three
divisions of time--past, present, and future; with the three realms of
the visible world--sky, earth, and sea; with the three constituents
of man--body, soul, and spirit; with the threefold enemies of
man--the world, the flesh, and the devil; with the three kingdoms in
nature--mineral, vegetable, and animal; with "the three colours"--red,
yellow, and blue; with "the three eyes of the honey-bee"--and with a
multitude of other analogues equally precious. The sacred power of the
number seven was seen in the seven golden candlesticks and the seven
churches in the Apocalypse; in the seven cardinal virtues and the seven
deadly sins; in the seven liberal arts and the seven devilish arts, and,
above all, in the seven sacraments. And as this proved in astrology that
there could be only seven planets, so it proved in alchemy that there
must be exactly seven metals. The twelve apostles were connected with
the twelve signs in the zodiac, and with much in physical science.
The seventy-two disciples, the seventy-two interpreters of the Old
Testament, the seventy-two mystical names of God, were connected with
the alleged fact in anatomy that there were seventy-two joints in the
human frame.

Then, also, there were revived such theologic and metaphysical
substitutes for scientific thought as the declaration that the perfect
line is a circle, and hence that the planets must move in absolute
circles--a statement which led astronomy astray even when the
great truths of the Copernican theory were well in sight; also, the
declaration that nature abhors a vacuum--a statement which led physics
astray until Torricelli made his experiments; also, the declaration that
we see the lightning