Catholics accepted the canon of the Bible--the Alexandrian
canon of the Old Testament--as a matter of uncontested faith.
Since it was not a matter of controversy for sixteen centuries,
there was no need to define the canon as infallible truth.
Septuagint papyrus manuscript
Duke Papyrus 740.
Fragment of a fourth century
Septuagint manuscript. Psalm 89:4-7.

...I will establish thy seed forever,
and build up thy throne to all generations.
 The heavens shall declare thy wonders,
O Lord; and thy truth in the assembly of the
saints. For who in the heavens shall be
compared to the Lord? And who shall be
likened to the Lord among the sons of
God? God is glorified...