But probably Vico was stimulated to the establishment of his criterion less by certain tendencies of Scotism or by current opinions than by the philosophers of the Renaissance, which he considered the golden age of metaphysical study, when shone, as he says, "Marsilio Ficino, Pico della Mirandola, Augustino Nifo and Augustino Steuco, Jacopo Mazzoni, Alessandro Piccolomini, Matteo Acquaviva and Francesco Patrizio."[25] In Ficino, whose name he couples with those of Plato and Plotinus,[26] and especially in his _Theologia Platonica,_ Vico could read a magnificent description of the productive character of the divine wisdom and its parallelism with that of the geometrician. Nature, says Ficino, which is divine art, differs from human art in that it produces its creations from within, by living reasons: and "it does not touch the surface of matter by means of a hand or any other external instrument, as the soul of a geometer touches the dust when he describes figures upon the earth, but _perinde ut geometrica mens materiam intrinsecus phantasticam fabricat,_ it operates like the mind of a geometer creating an imaginary matter from within itself. For as the geometer's mind, while it considers within itself the nature of figures, forms internally by pictures the image of figures, and by means of this image forms an imaginary spirit without any toil or design, so in the divine art of nature a wisdom of some kind by means of intellectual processes endows with natural seeds the life-giving and motive force itself which is its companion."[27] Vico must have recalled this passage in Ficino when in his inaugural lecture of 1699 he compared God, "the artist of nature," to the human mind which "we may without impiety call the God of art," just as he must have remembered it in the _De antiquissima_ where he compares God to the geometrician.[28] Vico might however have found thoughts of this kind in various Renaissance philosophers, not only in Ficino: among others, in Girolamo Cardano, who contrasts divine and human knowledge, though with a different conclusion; and restricts the one to finite objects ("for understanding is brought about by a kind of proportion, _proportione quaderni fit,_ and there is no proportion between the infinite and the finite"), denying that man can know God, for as Vico said later in almost the same words, "if I knew God, I should be God," _si scirem Deus essem._ Thus he postulated "other sciences, and other modes of understanding, entirely different from this of ours; more true, more solid, more firm, as a body is than its shadow: and again other principles which we can by no reason apprehend." And not only did he postulate them, but among the human sciences he observed one which as opposed to the natural sciences reached not merely the surfaces of things but almost the things themselves, namely mathematics. "The human soul, situated in the body, cannot attain to the substances of things,