It seems to me then that the difference which he begins by laying down between mathematics and physical science is considerably obscured in the sequel. And indeed how could Torricelli have seriously thought that the foundation of mathematics was a "fiction," when among his lectures one heard the title "in Praise of Mathematics"? In this lecture he says, quite in the Galilean style: "That to read the great Book of the Universe, the book on whose pages may be found the true philosophy written by God, mathematics are indispensable, will be seen by any one who with noble thoughts aspires to the science of the integral parts and greatest members of this huge body we call the World. The one alphabet, the only characters with which we can read the great manuscript of the divine philosophy in the book of the Universe are those poor figures you see in the text-books of geometry."[55] The most we can see in these statements is a vague and hazy presentment of the profound difference between physical truths and the so-called truths of mathematics. In conclusion, until for the third of my three points we can discover much more obvious "sources" than those suggested up till now, I shall see no cause to modify my verdict upon the originality of Vico's conception of mathematics. This originality is further proved by the important consequences drawn by Vico from his theory of mathematics for his philosophical method; for every one knows that a thought taken over bodily from another remains inert and sterile, while an original idea is always active and fruitful. _Note._--I have selected, of the various criticisms directed against my book on Vico, that concerning his "originality," because this gave me opportunities for researches and explanations of some value. But my book has been subjected to two general criticisms which do not lend themselves to the same treatment.