Development of Doctrine

GKC, Thomas Aquinas, chapter 1.

In short, it was what is technically called a Development in doctrine. But there seems to be a queer ignorance, not only about the technical, but the natural meaning of the word Development. The critics of Catholic theology seem to suppose that it is not so much an evolution as an evasion; that it is at best an adaptation. They fancy that its very success is the success of surrender. But that is not the natural meaning of the word Development. When we talk of a child being well-developed, we mean that he has grown bigger and stronger with his own strength; not that he is padded with borrowed pillows or walks on stilts to make him look taller. When we say that a puppy develops into a dog, we do not mean that his growth is a gradual compromise with a cat; we mean that he becomes more doggy and not less. Development is the expansion of all the possibilities and implications of a doctrine, as there is time to distinguish them and draw them out; and the point here is that the enlargement of medieval theology was simply the full comprehension of that theology.

The Thomist movement in metaphysics, like the Franciscan movement in morals and manners, was an enlargement and a liberation, it was emphatically a growth of Christian theology from within; it was emphatically not a shrinking of Christian theology under heathen or even human influences.

Nobody can understand the greatness of the thirteenth century, who does not realise that it was a great growth of new things produced by a living thing.