It is upon two encyclicals, Providentissimus Deus by Leo
XIII, Nov. 1893, and Divino Afflante Spiritu, by Pius XII, Sept. 30, 1943, that
the modernists of these latter days seize most readily as offering some support
for their cause which is utterly to discredit the words of Divine Revelation,
especially applied to references touching the physical sciences.
In Denzinger the relevant numbers are D l947-l948 and D
2294.
Leo XIII lays it down as a rule “not to depart in the least
from the literal and, as it were, plain sense, unless where reason forbids him
to hold it or necessity compels him to abandon it.” He goes on to say that “the
Church has received such a method of interpretation from the Apostles, and has approved of it by her own example, as is clear from
the liturgy.”
Now Leo does not specify at all or give any particular
examples in the passages held up by the modernists as granting some kind of
sanction to heliocentrism. Neither geocentrism nor heliocentrism is mentioned
in the encyclical.