“The totality of what exists, including what has existed and will exist, is infinitely small in comparison with the totality of the objects of knowledge. This fact easily goes unnoticed, probably because the lively interest in reality which is part of our nature tends to favor that exaggeration which finds the non-real a mere nothing (...) or, more precisely, which finds the non-real to be something for which science has no application or at least no application of any worth.”