In the Physics / Astronomy / "Water on Juipter" thread I slipped in C S Lewis's so-called Science Series. I had a comment I wanted to add but not there. Anyone who read these three books, can follow, I think.
Knowing C S Lewis's writings, I wonder how this series came to be called "science". I have never seen an authoritative comment on this and, until I do - maybe even then - my notion is that Lewis would have disagreed.
C S Lewis dedicated his life to spreading Christianity around the world and almost all his writings were about religion. Here is where those who have read this series come in. If you remember, everywhere Ransom went, there was religion and Earth was banished from the Solar System's community for going astray.
My contention is that Lewis would have called this a morality series. I suspect it got classified as science - or, better, science fiction - later by the unknowing and/or because science and science fiction were becoming very popular topics. I'd be interested in anyone else's thoughts.