HKB
In vain does St. Ambrose, in the sixth century, say (On Abraham, liv. ii., ch. viii.)--"We recognize nothing but the material, except the venerable Trinity alone."
The body of the entire Church has decided that the soul is immaterial. These saints fell into an error at that time universal; they were men; but they were not mistaken over immortality, because that is clearly announced in the Gospels.
We have so evident a need of the decision of the infallible Church on these points of philosophy, that we have not indeed by ourselves any sufficient notion of what is called "pure spirit," and of what is named "matter." Pure spirit is an expression which gives us no idea; and we know matter only by a few phenomena. We know it so little that we call it "substance"; well, the word substance means "that which is under"; but what is under will be eternally hidden from us. What is under is the Creator's secret; and this secret of the Creator is everywhere. We do not know either how we receive life, or how we give it, or how we grow, or how we digest, or how we sleep, or how we think, or how we feel.
The great difficulty is to understand how a being, whoever he be, has thoughts.