Long but so worth it
[note: “Model” refers to what we might call a “world view” or even a “metanarrative.” Lewis describes the Medieval Model as the “medieval synthesis…the whole organization of their theology, science and history into a single complex harmonious mental Model of the Universe.” P. 11]
The most spectacular differences between the Medieval Model and our own concern astronomy and biology. In both fields the new Model is supported by a wealth of empirical evidence. But we should misrepresent the historical process if we said that the irruption of new facts was the sole cause of the alteration.
The old astronomy was not, in any exact sense, “refuted” by the telescope….neither theological prejudice nor vested interests can permanently keep in favor a Model which is seen to be grossly uneconomical. The new astronomy triumphed not because the case for the old became desperate, but because the new was a better tool….
But the change of Models did not involve astronomy alone. It involved also, in biology, the change –arguably more important—from a devolutionary to an evolutionary scheme; from a cosmology in which it was axiomatic that “all perfect things precede all imperfect things” to one in which it is axiomatic that “the starting point is always lower than what is developed” (the degree of change can be gauged by the fact that primitive is not in most contexts a pejorative term).
...The demand for a developing world—a demand obviously in harmony both with the revolutionary and the romantic temper—grows up first; when it is full grown the scientists go to work and discover the evidence on which our belief in that sort of universe would now be held to rest. There is no question here of the old Model’s being shattered by the inrush of new phenomena. The truth would seem to be the reverse; that when changes in the human mind produce a sufficient disrelish of the old Model and a sufficient hankering for some new one, phenomena to support that new one will obediently turn up. I do not at all mean that these new phenomena are illusory. Nature has all sorts of phenomena in stock and can suit many different tastes….
I hope no one will think that I am recommending a return to the Medieval Model. I am only suggesting considerations that may induce us to regard all Models in the right was, respecting each and idolizing none. We are all, very properly, familiar with the idea that in ever age the human mind is deeply influenced by the accepted Model of the universe. But there is a two-way traffic; the Model is also influenced by the prevailing temper of mind….We can no longer dismiss the change of Models as a simple progress from error to truth. No Model is a catalogue of ultimate realities, and none is a mere fantasy. Each is a serious attempt to get in all the phenomena know at a given period, and each succeeds in getting in a great many. But also, no less surely, each reflects the prevalent psychology of an age almost as much as it reflects the state of that age’s knowledge. Hardly any battery of new facts could have persuaded a Greek that the universe had such an attribute so repugnant to him as infinity; hardly any such battery could persuade a modern that it is hierarchical.
It is not impossible that our own Model will dies a violent death, ruthlessly smashed by an unprovoked assault of new facts…But I think it more likely to change when, and because, far-reaching changes in the mental temper of our descendants demand that it should. The new Model will not be set up without evidence, but the evidence will turn up when the inner need for it becomes sufficiently great. It will be true evidence. But nature gives most of her evidence in answer to the questions we ask here. Here, as in the courts, the character of the evidence depends on the shape of the examination, and a good cross-examiner can do wonders. He will not indeed elicit falsehoods from an honest witness. But in relation to the total truth in the whiteness’s mind, the structure of the examination is like a stencil. It determines how much of that total truth will appear and what pattern it will suggest.
C.S. Lewis. The Discarded Image: an Introduction to Medieval and Renaissance Literature. Epilogue. p. 219-223