Hard SF? II

It is in The Armies Of Elfland (New York, 1992) that Poul Anderson introduces "The Queen of Air and Darkness" by saying, first, that it:

"...is not fantasy but science fiction." (p. 1)

- and, secondly, that:

"...it might be considered 'hard' science fiction, for it supposes nothing that a modern scientist would say is outright impossible, such as travel faster than light. (Granted, telepathy is controversial: but if it exists, presumably it operates within the framework of known natural law.)" (ibid.)

This suggests a tripartite distinction between fantasy, hard sf and, by implication, "soft" sf. I suppose it makes sense to say that:

Ray Bradbury wrote fantasy (The October Country) and soft sf (The Martian Chronicles; Fahrenheit 451) but no hard sf;
CS Lewis wrote fantasy (Narnia) and soft sf (Ransom) but no hard sf;
Poul Anderson wrote fantasy (various) and hard sf (also various) but no soft sf?

In fact, does anyone write both kinds of sf? Apart from these two big names, Bradbury and Lewis, all the sf that I have read seems to have been hard, I think.

(Having put Bradbury and Lewis side by side, it becomes possible to discern some remote thematic parallels between their works: an inhabitable, inhabited Mars and a repressive society on Earth - Lewis' version of the latter being the rule of the National Institute for Coordinated Experiment in the third Ransom novel.)

I am still surprised at Anderson's suggestion that faster than light (FTL) travel is not hard sf. Also, telepathy always counts as sf and is certainly hard when scientifically rationalized by Anderson and, several times, by James Blish.