We now apply these laws of mental processes, to which the explanation of our own inner consciousness leads, to explain the order and adaptation obser… - Bernhard Riemann

The adaptation observed in men, animals and plants... one part of this adaptation is explained from a thought-process in the interior of these bodies... another part, however, the adaptation of the organism, by a thought-process in a greater whole.

The word hypothesis has now a somewhat different significance from that given it by Newton. We are now accustomed to understand by hypothesis all thoughts connected with the phenomena.
Newton was far from the crude thought that explanation of phenomena could be attained by abstraction.

II. Thesis. In order that decision by arbitrary power may be possible in spite of completely definite laws of the action of ideas, one must assume that the psychic mechanism itself has, or at least in its development acquires, the peculiar property of inducing the necessity of these laws. Antithesis. No one can, in case of affairs, abandon the conviction that the future is co-determined by his transactions.