The development of doctrine is a notion more frequently invoked than understood. When, as is too often done, a novelty or even a reversal of traditional Christian teaching is proposed as a “development,” the term is being abused. Indeed, it is being deployed to denote precisely the opposite of what the Church’s greatest theorists of dogmatic development, SS. Vincent of Lérins and John Henry Newman, had in mind. Doctrine develops when hitherto unforeseen implications of the deposit of faith are drawn out of it. It is corrupted when that deposit is contradicted or new teaching is spun out of whole cloth. If what I know at first is that all men are mortal and that Socrates is a man, an inference to the effect that Socrates is mortal would be a development. Somehow to infer instead that Socrates is immortal or that roses are red would be something else entirely.
Catholics speak of “the mind of the Church” because the Church is a kind of corporate person. That a true development is always consistent with the past reflects the fact that hers is a logical mind. It also reflects her nature as an organism that grows as other living things do, yet, unlike them, is divinely preserved from deformation. Chesterton once wrote:
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.
