Latin for "philosophy (is) the servant of theology."
An idea espoused by Thomas Aquinas. Philosophy here is meant in the broadest sense of the word, i.e., including science.
The idea sounds quite bad to modern mind, especially considering the common conflict between science and religion (not all religion, mind you), as it seems to imply that that dogma should win over rational thought.
However, that is a later interpretation, or rather misinterpretation. Before Aquinas, theology was not concerned with rational thought, while Aquinas insisted that theology must use philosophy (in the broad sense) as its tool. The idea was to improve theology, not to enslave philosophy.
Indeed, before Aquinas' thought became the official form of Catholic theology, he was viewed with suspicion, as a heretic for his introduction of Aristotelian philosophy into theology. Since Aristotle was a pre-Christian philosopher, Aquinas's thought was originally seen as introducing paganism into Christianity.