Pope Pius XII Quote

Science descends ever more deeply into the hidden recesses of things, but it must halt at a certain point when questions arise which cannot be settled by means of sense observations. At that point the scientist needs a light which is capable of revealing to him truth which entirely escapes his senses. This light is philosophy.

In: Philip G. Fothergill, Life and Its Origin, Pontifical Academy of Science, Meeting 1955 (p. 12)