"... Any two opposite opinions are absolutely identical.
All that begins has a cause (Vallet).
It was very soon clear to me that antinomies must have some exploration. I found the contrast of two opinions a false: contrast. To contrast two things, it is needful that they should be of the same nature. I can contrast an apple and a pear, but not an apple and a cat. And the fact of these theories being antithetic I found to be the fact that they are of a different nature, one being a priori, the other being deduced from experience."
Fernando Pessoa [escrito em 1906]