C.S Lewis and why astrology still matters

You may have opened up your social media platform of choice one day to discover this bit of humor on your dashboard:

I laughed when I saw this ‘horoscope’ for the first time, but I also frowned. Why I laughed is obvious, but I will need to explain why I frowned.

Since the image is supposed to be humorous, let me begin with a lighthearted observation:

Scientifically speaking, the stars and planets actually do affect your life.

According to Newton’s law of universal gravitation, every particle in the universe attracts every other particle in the universe. In other wards, the particles which make up VY Canis Majoris have been tugging at you from the moment you were born, and are still tugging on you this moment.

Now, as I said at the start. This is merely a lighthearted observation. I don’t mean to say that because the stars and planets affect you through gravity, you can learn something about your destiny or the fate of mankind simply by observing their motion. Like you, I regard that as unscientific poppycock.

However, that’s where my real concern truly begins. Most people think they are above ‘astrological thinking’, simply because they don’t open the dailies to have a look at their weekly horoscope, and they don’t obsessively dig for the Zodiac sign of their significant others.

But in his work The Discarded Image, C.S Lewis gave some great insight into the reasoning behind astrology, and why it was once regarded as a useful practice by the Medievals.

As above, so below

As far as the Medievals were concerned, celestial bodies moved with an exact precision which admitted no idiosyncrasy. Lacking instruments to observe minute details about the stars or planets, the sky they observed seemed absolutely fixed, and never varied or changed in any way.

Of course, we know the Medievals were wrong on this point. We know that stars explode and collide, that new stars form, and that galaxies shift very slowly (on a scale of billions of years). But the Medievals didn’t know any of that, and they can’t be blamed for not knowing any of that. To them, outer space seemed like a fixed system, and this sort of perfection demanded a very rigorous, mathematical explanation.

Therefore, in Medieval scientific thinking, motion in the universe could be described from the top down, beginning with God who moved the Heavens, which in turn moved the planets and the stars. Lest anyone blame Christian Theology for this idea, we should recognize that the model was largely based on the thinking of Aristotle, who – in his De Caelo – tried to work out the origin of motion in a similar way.

Lewis puts it this way in Discarded Image,

All power, movement, and efficacy descend from God to the Primum Mobile and cause it to rotate; the exact kind of causality involved will be considered later. The rotation of the Primum Mobile causes that of the Stellatum, which causes that of the sphere of Saturn, and so on, down to the last moving sphere, that of the Moon.

This system, in turn, transmits motion to the Earth. Not that the Earth itself moves (of course, Medievals thought it was stationary), but things on the Earth move quite a bit. As such, the moon, along with all the other celestial bodies, exerted subtle affects on the Earth itself.

Besides movement, the spheres transmit (to the Earth) what are called Influences – the subject-matter of Astrology.

So it followed to the Medieval thinker that by understanding the motion of stars, planets and galaxies, one could also predict what would happen on Earth – calamity, the path of an individual’s life, and so on.

A modern kind of astrology

While it’s good to understand why people a long time ago believed what they believed, I worry that we are not careful enough to realize we aren’t so different. In our own age, we have of course discovered that the Universe is quite different from how the Medievals imagined it.

However, we may not be so different from the Medievals after all, at least when it comes to our general approach to understanding life.

While the Medievals thought ‘influence‘ began at the very top of the food chain and trickled down to human beings, we are rather inclined to believe the reverse. Because we have learned about DNA, molecules, quantum physics and biology, we might very well believe that ‘as below, so above‘.

As Richard Dawkins the eminent evolutionary biologist and atheist put it,

DNA neither cares nor knows. DNA just is. And we dance to its music.

The idea of human beings ‘dancing’ to the order prescribed to them by DNA is really no different from the Medieval idea that humans ‘dance’ to the motion of the stars, and as such, modern Science has put Christians in the same predicament that Astrology put the old Christians.


Yet Dawkins is no longer in vogue, and neither is pure determinism. Though there are still many sworn fatalists in the world, there are many more compatabilists. Beware, all the same. Old habits die hard, and astrological thinking can still be found in many forms. The atoms, molecules, DNA strands and chemicals of our body; our upbringings, social status, economic class and racial ‘privileges’ form constellations of stars and planets within us, and to them, many are prepared to pay the same homage as the Medievals did to the stars and planets without us.

Lewis notes about the opinion of the Medieval church on Astrology,

She fought against…astrological determinism. The doctrine of influences could be carried so far as to exclude free will. Against this determinism, as in later ages against other forms of determinism, theology had to make a defence. Aquinas treats the question very clearly. On the physical side the influence of the spheres is unquestioned. Celestial bodies affect terrestrial bodies, including those of men. And by affecting our bodies they can, but need not, affect our reason and our will. They can, because our higher faculties certainly receive something (accipiunt) from our lower. They need not, because any alteration of our imaginative power produced in this way generates, not a necessity, but only a propensity, to act thus or thus. The propensity can be resisted; hence the wise man will over-rule the stars.

I believe we can learn a valuable lesson from the struggles faced by the old theologians in light of an apparent scientific fact, which is now known to be hogwash. On the one hand, we cannot deny the influences which human beings receive from genes, sociological factors, hormones in the brain, etc. But on the other hand, we must never suppose that we ‘boil down’ to these things; that our whole nature and character are really exactly that of our influences.

We must recognize them for what they really are: influences, and not excuses, not causes, nor shackles nor laws.