Vico makes no kind of mention of the formula ens et verum convertuntur, though he knows and quotes—a fact which has escaped my critics—the analogous phrase "the true and the good are convertible," verum et bonum convertuntur:[9] a formula which he diverts to his own purposes, or rather unites it with his own. "In the first place," he writes, "I establish a truth which is convertible with the created, and in this sense I understand the good of the schools, convertible with existence: and hence I infer that the one and only truth is in God, since in Him is contained all Creation."[10] This union is reached quite openly by identifying verum with factum, then factum with ens, and finally the verum-factum-ens with the bonum: by substituting the doctrine of Vico for that of the schools. By such a method of interpretation one could reduce all doctrines to a single one, a perennis philosophia. I do not say that it would be a method entirely devoid of truth; but it is certainly not a historical method.
That Vico's criterion is not only different from but inconsistent with Thomism was shown, as I have already said, by Balmes; who pronounced it "specious but devoid of solid foundation." He uses St. Thomas's statements to controvert Vico's theological doctrine that God understands because He creates, opposing to it the Scholastic view that He creates because He understands. He denies, that the Word was conceived by the mere knowledge of what is contained in the divine omnipotence, for it is conceived not simply by creatures but also and chiefly by the cognition of the divine essence ("for the Father by understanding himself and the Son and the Holy Ghost and all other things embraced by His knowledge conceives the Word, so that thus the whole Trinity is implied in the Word, and also every creature": Pater enim intellegendo se et Filium et Spiritum sanctum et omnia alia quae ejus scientia continentur concipit Verbum, ut sic tota Trinitas Verbo dicatur, et etiam omnis creatura); he objects that, granting this criterion, God could never know himself, because He is not His own cause. He denies that intelligence is only possible through causality, inasmuch as it is also possible through identity. He accuses Vico's criterion of involving scepticism: in a word he maintains that the facts of knowledge are known by reason, even if they are not the products of reason.[11] I am not concerned to ask whether Balmes is right, or whether Vico's criterion can be reconciled with Christian theology. I am concerned merely with establishing, not only by quotation from St. Thomas but also by the help of the judgment of an authoritative interpreter of his system that this doctrine is not Thomistic.
Even granting that the criterion in question is irreconcilable with Thomism but not with an improved Christian theology, it is certainly irreconcilable with both in the form it adopts in what I have called "Vico's second theory of knowledge," in the Scienza Nuova, which Balmes either did not know or omitted to mention, and is passed over by my critics with a light-heartedness that is not particularly enviable. One of them asserts that "the alleged distinction" (the distinction that is drawn by myself) "between Vico's first and second theories of knowledge does not in point of fact exist, and produces no effects of any kind." What? Has it no effects, when those historical studies and sciences of mind, which in the De antiquissima occupied the lowest position among mere probabilities became in the Scienza Nuova the truest of all—true even in a higher degree than mathematics itself as dealing with the human world which "is man's creation?" when their form is found "in the modifications of the actual human mind itself?" when they have "a reality as much greater, as the reality of the laws of human affairs is greater than that of points, lines, areas and figures?"[12] Is there no distinction, when we pass from the scepticism of the De antiquissima to the rationalism of the statement that these "proofs are of a divine nature," and must produce "a divine pleasure, since in God to know and to create are one and the same"?[13]
It is true that upon this point my attention has been recalled to a well-known passage of Galileo (Dialogo dei massimi sistemi), an especial favourite of our own Spaventa,[14] where we find the thought that the human intellect differs from the divine extensivè, but not intensivè, and that if the divine intellect knows infinitely more about mathematical propositions because it knows them all, yet "of these few facts known by the human intellect, its knowledge is equal to that of the divine in objective certainty, since it attains comprehension of the necessity than which no greater certainty, it seems, can exist." But in any case Galileo was not a Schoolman, and moreover this pronouncement of his seemed so dangerous to the Christian theory of ideas, that he himself was obliged to alter it by admitting that while "so far as the truth of which mathematical proof gives no knowledge is concerned, this is identical with that which the divine wisdom knows," yet "the manner, in which God knows the infinitely numerous propositions of which we know a few, is immensely superior to our own, which proceeds discursively from one conclusion to another, while His is simple intuition." It is important too not to forget that this very statement figures among the heads of the accusation in Galileo's trial.[15]
If the formula of the conversion of the true with the created is not found in Thomism, it may perhaps be found, at least in its original, sceptical or mystical, intention, in other tendencies of scholasticism or mediaeval philosophy generally. With Thomism Vico seems to have had neither acquaintance nor sympathy: but from his autobiography it is plain that he studied nominalism and the summaries of Petrus Hispanus and Paulus Venetus, though with little profit,[16] and later also, much more profitably, the Scotist philosophy; which he considered the most Platonic of the Scholastic systems.[17] Traces of this appear in several views expressed in the De antiquissima, especially in those dealing with universals and ideas. In this direction, the direction that is to say of the Scotist system and the closely allied system of Occamism, I have attempted various researches, without attaining any remarkable results: further, I have applied for assistance to various specialists in Scholasticism, but in vain; they would do nothing but express their own superficial impressions or lose themselves in idle disputation. In general it seems possible to say that Duns Scotus's theory of knowledge presents points of affinity to that of Vico: for example, in the polemic against the Thomistic doctrine of the adaequatio intellectus et rei, which he refutes by applying it to the divine knowledge, since God knows objects as willed by Him, and they exist because He wills their existence without His being necessitated by them.[18] For Occam again the thought of objects has no reality and objectivity (or subjectivity according to the usage of Scholastic terminology, which is the reverse of modern) in God, and is nothing else than the objects themselves, known by God according to the possibility of creating them, in virtue of which they are thinkable to the divine mind.[19] But the question for Vico is not merely the priority of creation to knowledge or knowledge to creation, but the convertibility or identity of knowledge and creation.
In certain recently published philosophical observations by Paolo Sarpi,[20] a nominalist of Occam's school,[21] the following statements are to be found. They are the more notable because standing as they do without any results in Sarpi's thought and being undeveloped in subsequent philosophy, they seem to be not his own invention but a mere repetition of scholastic dicta. "We have certain knowledge both of the existence and of the cause of those things which we understand fully how to create: of those which we know by experience, we know the existence, but not the cause. We can however guess at it, and look simply for a possible cause: but out of many found to be possible we cannot be certain which is the true one. This fact may be seen in descriptions of astronomical theories, and would also be true in the case of a man who saw a clock for the first time. Of the various guesses, that of a man who knew how to make similar objects would be nearest the truth, e.g. one who understood the construction of machinery when he saw a different kind of machine: but none the less he will never on that account[22] know for certain. There are then three kinds of knowledge: first, knowledge how to make the object: secondly, experience of it: and thirdly, guessing at possibilities." This thought, then, namely that objects are known by their creator, and that God knows objects because He creates them, seems to have been current in the schools: and this explains the fact of its reappearing in an incidental manner and as an obvious truth in Francesco Sanchez's Quod nihil scitur (1581) where it is declared impossible "perfecte cognoscere quis quae non creavit; nec Deus creare potuisset nec creata regere quae non perfecte precognovisset"[23] (that one should know perfectly things which he has not created: nor could God have been able to create nor after creating them to control things which He had not perfectly foreknown).
But need we continue to look for it in the guise of a casual remark or an isolated proposition, devoid of philosophical connexion, in the works of philosophers or the lecture-rooms of the schools? Did it not simply form a part of the common thought which daily declares that the man who has made a thing knows it better than he who has not made it? Probably a little attention would reveal it in many and dissimilar treatises; and for my own part, while reading the Chronicon of Otto of Freising the other day, I came across it in the introduction to the third book, where the chronicler, writing as is well known under the influence of St. Augustine's Civitas Dei, is arrested by the objection that God's designs in history are inscrutable, and delivers himself of the following reflections: "What then shall we do? If we cannot understand, shall we hold our peace? Then who will reply to those who flatter, repel those who attack, and by the reason and might of his words confute those who would destroy the faith that is in us? So we cannot understand the secret counsels of God, and yet we are often compelled to give a reasonable account of these things. What? Shall we reason about things which we do not understand? We can give reasons, but human reasons, when yet we cannot understand the divine reasons. And thus it happens that when we speak of theological matters, lacking the right words for them, we being men use our own words; and in speaking of so great a God in human language, we use our words the more boldly quo ipsum figmentum nostrum cognoscere non dubitamus, because we never doubt that we know the thing we have ourselves formed: quis enim melius cognoscit quam qui creavit? for who knows a thing better than he who has created it?"[24] The logic of the Abbot of Freising at this point may be thought a trifle sophistical: but the fact remains that he refers to a common opinion that he knows things who has made them.
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, but wanders about upon their surfaces by the help of the senses, examining measurements, actions, resemblances and doctrines. But the knowledge of the mind, which creates the fact, is in a sense itself the fact, just as even among human sciences the knowledge of a triangle, that it has three angles equal to two right angles, is practically identical with the truth itself (scientia vero mentis, quae res facit, est quasi ipsa res, veluti etiam in humanis scientia trigoni, quod habeat tres angulos duobus rectis aequales, eadem ferme est ipsi veritati), whence it is clear that there is in us a natural science of a different kind from true science."[29] Here, in the definition of divine knowledge and of the procedure of human knowledge in the case of mathematics, as opposed to that of physical science, is implicit the principle that true knowledge consists in the identity of thought with its object.
The idea of the opposition of mathematics to physical science, in the certainty of the one and the uncertainty of the other, persisted in the Neapolitan philosophers and scientists of Vico's youth, even if they lost sight of the reason of this opposition. Tommaso Cornelio in his "progymnasma" De ratione philosophandi (1661) after reviewing the errors produced by the illusions of sense in physical science, says, "the contemplations of mathematics are not subjected to errors of this kind, dealing as they do with things whose images are not introduced into the mind by the senses; for the mind can by itself adequately conceive figures and numbers, whose properties and analogies are examined by mathematicians, without aid from sense."[30] This ought to be emphasised, since it seems highly probable that Vico was stimulated to the establishment of his general theory of knowledge by reflection upon mathematics and the contrast between it and physical science. In fact the Latin speeches, our earliest documents for his studies, though they show the influence of Ficino and a certain amount of Cartesianism,[31] are never dominated by this general criterion. It is only in the last of these speeches, that of 1707, that the distinction between mathematics and natural science begins to appear; in the next year it is clearly stated in the De ratione studiorum, where it takes the form of a general criterion. "We demonstrate geometry because we make it: if we could demonstrate physical facts, we should be creating them. For the true forms of things exist only in God the greatest and best, and to these the nature of them conforms" (geometrica demonstramus quia facimus: si physica demonstrare possemus, faceremus. In uno enim Deo Opt. Max. sunt verae rerum formae, quibus earundem est conformata natura). And this theory attained its full development in 1710 in the De antiquissima.
Such are the probable precedents, or as the common but inaccurate metaphor expresses it, "sources" of Vico's theory of knowledge. I do not think that the formation of this theory can have been influenced by the propositions of Geulinx and Malebranche which have been pointed out to me,[32] namely that "no one can make that which he does not know," and that "God alone knows his works, because he foreknows his action." In these propositions the old Thomistic doctrine is substantially summarised. Much more tenable would be a connexion or at least a comparison with Spinoza; we may recall the Spinozistic identification of the ordo et connexio idearum and the ordo et connexio rerum. Another ingenious, but I think, inaccurate view is that "the analytic geometry of Descartes was the introduction of the genetic principle into the study of geometrical objects," so that the principle verum ipsum factum "before being formulated by Vico had been practised by Descartes"; and Vico in the De antiquissima "adopted the scientific method of Descartes, which he stated as the convertibility of the true with the created," raising it "from a certitude to a criterion."[33] We are dealing here not with practice, but simply with the theory of method: for this method, conceived in its universality, just so far as it is practical has always been practised; not by Descartes alone, and not only by analytic geometry.