Medical Science in Space: Your Joy in God and Muscular Atrophy

When astronauts go into space for a long time, they often come back weakened, and they need months of therapy to regain normal muscle function. This is called the Trepp effect, and it usually means the strength of muscle contraction's as little as half of that muscle's previous strength.

What do astronauts have to do with our beloved Prometheus?

There's a lovely quote by C.S. Lewis,

“A perfect man would never act from sense of duty; he'd always want the right thing more than the wrong one. Duty is only a substitute for love (of God and of other people), like a crutch, which is a substitute for a leg. Most of us need the crutch at times; but of course it's idiotic to use the crutch when our own legs (our own loves, tastes, habits, etc.) can do the journey on their own!”¹

He's right of course. But it follows that if we decide to use the crutch all the time, even though we could walk, the leg we're not using will eventually undergo the Trepp effect, just like those astronauts. If we always rely on our sense of duty to do the right thing, eventually we'll find it very, very difficult to love anyone.

So what then? Should we just do the wrong thing until we feel like doing the right thing? Sin, that grace may abound? In one of his letters, Paul answers no. He says the fundamental thing is that we've been set free, not to sin, but to grace. Set free from sin, so the glory won't go to abounding sin on the planet, but to abounding love. How are we free?

Because of fire. Because there's a Spirit of fire, brought by our dear Prometheus, to whom all our meditations must return.

We must pray more earnestly for fire to arrive, that we may burn our crutches and walk in the light.

1Excerpt from letter to Joan, July 18, 1857, in C.S. Lewis: Letters to Children, de. Lyle W. Dorsett and Marjorie Lamp Mead (New York: Simon & Schuster, 1995), 276, quoted in John Piper's When I Don't Desire God: How to Fight for Joy