THE "SUMMA THEOLOGICA"

_xiv THE "SUMMA THEOLOGICA "
affection of evil can touch. Hence reason proves that God
is not only true, but the very Truth itself, which cannot
deceive or be deceived. Further, it is a clear consequence
from this that the human reason obtains for the word of
God full belief and authority.
In like manner reason declares that the evangelical doctrine
has shone as the light from its very beginning, by
signs and miracles which are infallible proofs of infallible
truth ; and that therefore they who receive the Faith by the
Gospel do not act rashly, as if they had ' followed cunningly
devised fables,' but, by an obedience that is altogether
reasonable, submit their understanding and their judgment
to the authority of God.
Further, not less than these things in value is it that
reason clearly shows us the truth about the Church instituted
by Christ. That Church, as the Vatican Synod decreed--
'because of the wonderful way in which it spreads; because
of its great holiness and inexhaustible fruitfulness
in all places ; because of its Catholic unity and invincible
stability--is in itself a great and perpetual motive of
credibility, and an unanswerable argument for its own
Divine legation.'
The foundations, then, having been laid in the most solid
way, there is needed, further, a use of philosophy, both perpetual
and manifold, in order that Sacred Theology may
assume and put on the nature, habit, and character of true
science. For in this noblest kind of learning it is above
everything necessary that the parts of heavenly doctrine,
being many and different, should be gathered together, as
it were, into one body. Thus they are united by a union
of harmony among themselves, all the parts being fittingly
arranged, and derived from their own proper principles.
Lastly, all of these parts, and each of them, must be
strengthened by unanswerable arguments suited to each
case.
Nor must we pass by in silence, or reckon of little account,
that fuller knowledge of our belief, and, as far as may be,
that clearer understanding of the mysteries of the faith