I judge that it ought to be adapted to seeing, and although its form, the character of all its parts, and their composition, when judged in accordance with merely mechanical laws, are entirely contingent as far as my own power of judgement is concerned, I nevertheless think that its form and structure manifest a certain necessity, namely one that accords with a concept which precedes the formative causes of the organ in question and without which I am incapable of conceiving of the possibility of this natural product under any mechanical laws of nature (something that is not the case with the stone).