THE "SUMMA THEOLOGICA"

ENCYCLICAL OF LEO XlII. xviJ
most certainly true, and that the arguments brought against
the Faith are not in accord with right reason, the Catholic
philosopher should bear in mind that he will violate the
rights both of Faith and reason, if he embrace any conclusion
which he understands to be contrary to revealed doctrine.
We know indeed that there are to be found men who,
exalting too highly the powers of human nature, contend
that the understanding of man falls from its native dignity
when it becomes subject to Divine authority, and that being
thus bound, as it were, in a yoke of slavery, it is greatly
retarded and hindered from reaching the heights of truth
and excellence. Such teaching as that is full of error and
falsehood. The end of it is that men, in the height of folly
and sinful thanklessness, reject all higher truths. They
deliberately cast away the Divine blessings of faith, from
which the streams of all good flow, even to civil society.
Now, the mind of man is shut up and held in certain bounds,
and narrow enough those boundaries are. The consequence
is that it falls into many mistakes and is ignorant of many
things. On the other hand, the Christian Faith, resting as
it does on the authority of God, is the certain teacher of
truth. He who follows this guidance is neither entangled
in the nets of error nor tossed about on the waves of doubt.
Hence the best philosophers are they who join philosophical
study with the obedience of the Christian Faith. Then the
brightness of Christian truths falls on the mind, and by that
brightness the understanding itself is helped. This takes
nothing from the dignity of the reason ; nay, rather, it adds
to the reason a great deal of grandeur and subtlety and
strength.
Worthily and most fruitfully do we use the keenness of
the understanding when we set ourselves to refute opinions
against the Faith, and to prove those things which agree
with it. For in disproving errors we ascertain their causes,
and then show the falsity of the arguments by which they
are bolstered up ; while in proving truths we _lse the force
of the reasons by which they are demonstrated with certainty,
and by which all prudent men are persuaded. If,