“Enq: What do you mean by sui generis?
Theo: I mean that, though the fundamental law and the universal working of laws of Nature are uniform, still our Solar system (like every other such system in the millions of others in Cosmos) and even our Earth, has its own programme of manifestations differing from the respective programmes of all others.
We speak of the inhabitants of other planets and imagine that if they are men, i.e., thinking entities, they must be as we are. The fancy of poets and painters and sculptors never fails to represent even the angels as a beautiful copy of man – plus wings.
We say that all this is an error and a delusion; because, if on this little earth alone one finds such a diversity in its flora, fauna and mankind – from the seaweed to the cedar of Lebanon, from the jelly-fish to the elephant, from the Bushman and negro to the Apollo Belvedere – alter the conditions cosmic and planetary, and there must be as a result quite a different flora, fauna and mankind.
The same laws will fashion quite a different set of things and beings even on this our plane, including in it all our planets.
How much more different then must be external nature in other Solar systems, and how foolish is it to judge of other stars and worlds and human beings by our own, as physical science does!”
H. P. Blavatsky