This remarkable work reads in part like science fiction, although it is based on solid scientific facts. The author turns the tables – or the light beam – and has observers look down on the earth from stars located at a variety of distances out in space. (…) This idea was crucial for the special theory of relativity: Time travels with light. (...) Einstein would later supply the scientific foundation for these kinds of fantasies.
Jürgen Neffe: Einstein – A Biography (2005)
It is one of the most strikingly suggestive books, and small though it is, one of the most remarkable of the present century.
Richard A. Proctor, Honorary Secretary of the Royal Astronomical Society (1880)
... it contains a fund of deep thought which larger works on astronomical subjects have seldom developed. It is most logically written. Step by step, from undeniable premises, does the writer prove his point, until the omniscience of the great one Deity is made apparent to our mental vision, and in an extraordinary new and clearer light.
Dolman's Magazine (1846)
It is one of the most poetical ideas which the human mind can entertain, — an idea which is not merely chimerical and imaginary, but based on scientific facts, and logically true. We wonder it has never been hit upon before.
Family Herald (1846)