In the Walking on the Water we see the relations of spirit and Nature so altered that Nature can be made to do whatever spirit pleases. This new obedience of Nature is, of course, not to be separated even in thought from spirit’s own obedience to the Father of Spirits. Apart from that proviso such obedience by Nature, if it were possible, would result in chaos: the evil dream of Magic arises from finite spirit’s longing to get that power without paying that price. The evil reality of lawless applied science (which is Magic’s son and heir) is actually reducing large tracts of Nature to disorder and sterility at this very moment. I do not know how radically Nature herself would need to be altered to make her thus obedient to spirits, when spirits have become wholly obedient to their source. One thing at least we must observe. If we are in fact spirits, not Nature’s offspring, then there must be some point (probably the brain) at which created spirit even now can produce effects on matter not by manipulation or technics but simply by the wish to do so. If that is what you mean by Magic then Magic is a reality manifested every time you move your hand or think a thought. And Nature, as we have seen, is not destroyed but rather perfected by her servitude.

Lewis, C. S.. Miracles (Collected Letters of C.S. Lewis) (p. 245). HarperCollins. Kindle Edition.