It is fairly easy to detect the immediate individual sources of much of Dee's thought - he draws extensively, for example, from Proclus, Cusa and Roger Bacon. Its location within a Platonic tradition can also be negatively delimited to some extent - he acknowledges no debt to Ficino, and references to purely "humanist" or "moral" philosophers are rare; Pico, despite his considerable reputation in England, served rather as a prophet than a guide, for though he constantly proclaims the power and importance of "magic," he laid down no clear methods that could be of direct assistance for the investigation or control of nature; indeed his general views on questions of natural science seem deeply influenced by his Averroist training and are of a relatively reactionary cast. An exposition, however, of the general metaphysical scheme and principles, which underlay or came to be associated with much of the new science, must be largely arbitrary in form, and, compared to the historical manifestation of this thought in the Renaissance, will be over explicit, and the divisions and distinctions it sets up artificial. For though the change introduced into science was simple and profound, the movement of thought that led to it was extremely complex and varied, and thoroughly eclectic. It grew up in close contact with the older thought and made use of it as far as possible. It did not in general directly oppose Aristotle, or denounce him as one who had "defaced the monument of the ancient metaphysical theology by his profane hands," (110) rather with some modifications and a general revaluation it incorporated much of his teachings into its own general synthesis. The Thomist reform had preserved a place for Plato in admitting his value as regards things spiritual, while making Aristotle an undisputed authority in the realm of natural things. The new thought, taking Platonic doctrine to have universal reference, allowed to Aristotle's work the status of a preliminary discipline, and accepted Aristotelianism as an heuristic provisional guide in a number of studies - notably medicine, in which the former could not widely or obviously be yet applied.

This reconciliation and incorporation had perhaps always been one of the characteristics of neoplatonism. The polemic of Atticus against Aristotle does not seem to have represented a very widespread or historically influential attitude. The fifth century academy under Syrianus explicitly labelled Aristotle's works as a propaedeutic to the study of Plato. Thus Marinus declares that Proclus studied Aristotle under Olympiodorus in Alexandria until he "felt that they [peripatetics] were no longer interpreting the text they were explaining in a spirit worthy of the philosopher" (Aristotle), and migrated to the Platonic Academy at Athens. For two years "Syrienus read with him all the writings of Aristotle in logic, ethics, politics, physics and even theology....as if they were preparatory rites or lesser mysteries," and afterwards "led him spontaneously....up to the greater mysteries of Plato, and revealed their truly divine visions to the untainted eyes of his soul and the pure gaze of his mind.(111) Ammonias Saccas had attempted to demonstrate the concordance of the two, and the Enneads of his disciple have been presented as representing a wedding of an Aristotelian metaphysic to a Platonist psychology (112) (to the mere "thinking" that Aristotle had allowed to the prime mover for example, he added the attributes of "will" and "love," and it is the god of Plotinus rather than of Aristotle that Aquinas later reproduced). The Aristotle of the middle ages - and it was still the Aristotle that Renaissance Platonism largely adopted - was a product of this conciliation. Boethius had presented them with a "platonised" Aristotle, and many of the works passing under Aristotle's name were compilations from purely Platonic sources. Thus the Theology, supposedly supplementing the Metaphysics, is taken from the last three books of Enneads, his "last work," the Liber de Pomo, translated into Latin at the command of Manfred of Sicily is a paraphrase or imitation of the Phaedo; the Liber de Causis is a translation from an Arabic work based on Proclus' Elements. It is from these works that, for example, the greater part of Roger Bacon's quotations from "Aristotle" are drawn, and they do much to explain how he reconciled his particular metaphysic with his explicit assertion that Aristotle was the greatest, and far greater than Plato, of all ancient philosophers. Such writings were rejected by Renaissance Aristotelians, attempting to rediscover and defend the historical Aristotle, on the ground of their spuriousness, but they continued to be accepted, if not as genuine, yet as valuable writings by many neoplatonists of the time, on the ground of their content.

That scientific Platonism meant rather an infusion of new ideas with the mass of materials offered by older thought, and not a rejection of it, was an inevitable consequence of the resources available. A reflection on this is that although Dee consciously tried to apply what he believed was a Platonic-Pythagorean approach to his personal investigations, yet his library list reveals that while he possessed some hundreds of commentaries and studies on the writings of Aristotle, there were but a handful, Chalcidius, Proclus, Pletho, etc. directly or solely concerned with the Platonic dialogues, and a similar proportion maintains between works dealing with Averroes and Avicenna. Plato himself was an inspiration rather than authority, no essential distinction was made between him and later followers. But this of course was merely the traditional view. Augustine always defers to the interpretations of Plotinus, since he regards him as the philosopher who most thoroughly understood and reproduced the thought of Plato (113), and he suggests that from their works they might naturally be mistaken for contemporaries. The very names of these two were confused in their Arabic transliteration, and the fusion passed without remark. Thomas Taylor, in many ways closer to Renaissance scholarship than that of his own day, continued the habit of interpreting Plato "absolutely" and unhistorically through Proclus, Plotinus and Porphyry, into the early nineteenth century (114). They were all indeed regarded as faithfully preserving a single, unified body of doctrine, as representing a tradition of which even Plato was not the originator, but which contained also the Chaldean Oracles, Hermes Trismegistus, Moses and Adam. Proclus according to his biographer Marinus, had said that he wished all books in the world could be burnt with the exception of the Timaeus and Chaldean Oracles (115), and it was the Timaeus - which had been the only specimen of Plato's original work available through much of the Middle Ages, that, perhaps along with the Epinomis, continued to be accepted by many scholars of the Renaissance as the principle treasure house of Platonic doctrines. Related to this attitude is the fact that many of the "Platonic" doctrines which were now most emphasized and turned to most account do not figure to any great extent in the dialogues, but are exposed fully and attributed explicitly to Plato in Aristotle's various criticisms of his thought. They concern primarily the nature of numbers and the function of mathematics (116a). Aristotle's interpretation of these views was frequently accepted in many details (important in this respect is his denial of any real difference between the natural science of the Platonists and Atomists, since both were ultimately trying to reduce all things to quantitative relationships (117a)). This accounts to some degree for the Pythagorean bias in later interpretation of Plato, which very often resulted in these two being regarded as practically equivalent. Both Platonists and Pythagoreans believed numbers to be the principle of things, Aristotle asserted (118a), and he maintained that there was no more than a verbal difference between the Pythagorean "Things imitate number" and the Platonic "Things participate number."(119a) Porphyry records that in his day the general charge was made against Plato of "stealing" Pythagorean doctrines; Aulus Gellius went so far as to give the fantastic prices supposedly paid by Plato for the works of Philolaus and had quoted Timon's poem accusing him of compiling the Timaeus from Pythagorean books (116b); thus in 1584 the learned Ranzovius refers to "Pythagorus, Italicae Philosophiae princepts, quem Plato pene in omnibus imitatur....(117b)