Nature produces many; but the consequence of our not being able to produce it by art is, that in every instance in which we see a human mind developing itself, or acting upon other things, we see it surrounded and obscured by an indefinite multitude of unascertainable circumstances, rendering the use of the common experimental methods almost delusive.
"A System Of Logic, Ratiocinative And Inductive (Vol. 1 of 2)"
John Stuart Mill
Circled with limitation unexceeded Our eyes behold exterior mysteries And gods unascertainable as these- Shadows and shapes irresolubly heeded; Phantoms that tower, and substance scarcely known.
"The Star-Treader and other poems"
Clark Ashton Smith
But there was certainly something uncanny about it, especially as from time to time noises and cries occurred there, which could not be heard outside the room and whose origin was unascertainable.
"Royal Highness"
Thomas Mann