, directed to the manifestation of the eternal glory of
God. The framework we may chiefly ascribe to Gregory VII; the content to
St. Thomas Aquinas. But the whole resultant unity is less the product of
great personalities than of a common instinct and a common conviction.
Men saw the world _sub specie unitatis_; and its kaleidoscopic variety
was insensibly focused into a single scheme under the stress of their
vision. The heavens showed forth the glory of God, and the firmament
declared His handiwork. Zoology became, like everything else, a willing
servant of Christianity; and _bestiaria moralizata_ were written to
show how all beasts were made for an ensample, and served for a type,
of the one and only truth. All things, indeed, were types and allegories
to this way of thinking; and just as every text in the Bible was an
allegory to mediaeval interpretation, so all things in the world of
creation, animate and inanimate, the jewel with its 'virtue' as well as
the beast with its 'moral', became allegories and parables of heavenly
meanings. Thus the world of perception became unreal, that it might be
transmuted into the real world of faith; and symbolism like that of Hugh
of St. Victor dominated men's thought, making all things (like the Mass
itself, if in a less degree) into _signa rei sacrae_.

The unity of knowledge was thus purchased at a price. Things must cease
to be studied in themselves, and must be allegorized into types, in
order that they might be reduced to a unity. Perhaps the purchase of
unity on terms such as these is a bad bargain; and it is at any rate
obvious that in such an atmosphere scientific thought will not flourish,
or man learn to adjust himself readily to the laws of his environment.
From the standpoint of natural science we may readily condemn the Middle
Ages and all their works; and we may prefer a single _Opus_ of Roger
Bacon to the whole of the _Summa_ of St. Thomas. But it is necessary to
judge an age which was destitute of natural science by some other
criterion than that of science; nor must we hasten to say that the
Middle Ages found the Universal so easily, because they ignored the
Particular so absolutely. The truth is, that though mediaeval thinkers
knew far more of the writings of Aristotle than they did of those of
Plato, they were none the less far better Platonists than they were
Aristotelians. If they had been better Aristotelians, they would have
been better biologists; but as th