C. S. Lewis in his own preface to "That Hideous Strength", notes: "I believe that one of the central ideas of this tale came into my head from conversations I had with a scientific colleague, some time before I met a rather similar suggestion in the works of Mr. Olaf Stapledon. If I am mistaken in this, Mr. Stapledon is so rich in invention that he can afford to lend, and I admire his invention (though not his philosophy) so much that I should feel no shame to borrow".