16th Century history hardly cut and dried

Historians of science and philosophy, and especially if they hold some theory of progress, are naturally interested in seizing those elements of sixteenth-century thought which were later to alter Man's whole picture of reality. Those other elements which were destined to disappear they tend to treat as mere 'survivals' from some earlier and darker age.

The literary historian, on the other hand, is concerned not with those ideas in his period which have since proved fruitful, but with those which seemed important at the time. He must even try to forget his knowledge of what comes after, and see the egg as if he did not know it was going to become a bird. From his point of view it is misleading to call the animistic  or genial cosmology of the sixteenth century a 'survival'.

For one thing, that word hardly does justice to the fact that it seems to be rather more lively and emphatic at this time than it had been before. For another, it carries the dangerous suggestion that this cosmology was now something alien and intrusive, no longer characteristic of the age. It teaches us to divide the men of that period into two camps, the conservative superstitious and the progressive or enlightened: even, possibly, to suppose that they would have agreed with our dichotomy.

In reality it would leave nearly every one of them a border-line case. The groupings of which they were conscious were quite different from those which our modern conceptions of superstition or enlightenment would impose on them...

[The] conflict between the magician and the astrologer seems very surprising to those who want to impose our modern grouping on the men of the past; for by our grouping magic and astrology go together as 'superstitions'. But the moment we drop our grouping (which is from the historical point of view irrelevant and accidental) and try to see these two arts as they appeared to their exponents, the thing becomes perfectly simple.

Magic and astrology, though of course often mixed in practice, are in tendency opposed. The magician asserts human omnipotence; the astrologer human impotence. The common emotion (whether of repulsion or whimsical curiosity) which unites them in our minds is modern: something on the lens of the glass we look through, not something in the historical object.

The thorough-going astrologer is a determinist. He holds the creed (in William James's words) of the 'tough-minded'. He shatters the illusions and despises the exciting hopes of the magician. Those tempermants that are attracted by modern forms of determinism in our own day would have been attracted by astrological determinism in the sixteenth century.

-- C.S. Lewis, English Literature in the Sixteeth Century, pp. 4-6.