"Der Aufstieg zum Einen" is the second edition of Jens Halfwassen's PhD thesis from 1989 (first edited 1991), now slightly augmented by a short, 7-page postscript with bibliographical additions, and Halfwassen's reactions to reviews and similar studies published since then.
The main thesis of "Der Aufstieg zum Einen" is that the "Metaphysik des Einen [...] keine Neubildung Plotins [ist], sondern -- das ist meine These -- sie ist in allen wesentlichen Aspekten schon bei Platon ausgebildet" (pp. 32-33). This means that Plotinus' ontology -- which should rather be called Plotinus' henology -- is a rather accurate philosophical renewal and continuation of Plato's unwritten doctrine, i.e. the doctrine rediscovered by Krämer and Gaiser.1
Though it is broad in its scope and its philosophical implications, Halfwassen nevertheless restricts his study to the dialectical process of understanding the metaphysical relations between the One and the Plurality: "Dieser dialektische Weg der Hinführung und des Aufstiegs zum Absoluten ist der wesentliche Inhalt der Metaphysik des Einen, er allein ist philosophisch explizierbar und auf ihn beschränkt sich auch die vorliegende Arbeit" (p. 15).
After a brief introduction (pp. 9-33), which is in some respects a synthesis of the general thesis of his book, Halfwassen presents a systematic summary of Plotinus' philosophy (pp. 34-182), which understands itself much more as an analysis and explanation of Plato's thought than an autonomous and independent metaphysical attempt. The essence of Neoplatonic thought lies in the assumption that nothing can be perceived and explained without recurring to the idea of Oneness, which is even necessary to our understanding of Plurality, being itself nothing else than a unique assembly of unique objects.
Throughout the first part of his book, Halfwassen gives a detailed account of Plotinus' view of the different ontological steps leading from nature, soul and mind to the One itself (pp. 34-52). He also analyses the attempts at a definition of the absolute Oneness beyond every Plurality as a necessary condition of every existence (pp. 53-97), and investigates the paradoxical difficulties of why the Plurality finally came into existence and why it should have been necessary for the unique One to bring the world into existence (pp. 98-149). Halfwassen finally underlines the absolute transcendence of the One itself, which surpasses existence, mind and cognition (pp. 150-182).
The second part of Halfwassen's thesis deals with the metaphysics of the One in the philosophical thought of Plato (183-405). Nevertheless, its first chapter is mainly concerned with a brief historical survey of the evolution of Monism in Greek thought (pp. 183-219). Taking the Eleatics as the first representatives of Monism, Halfwassen depicts the continuity of evolution from Parmenides to Plato and further to Plotinus. Halfwassen's main aim is to show that there is, in opposition to what is often the scientific consensus, a direct continuity between Plato and the Ancient Academy on the one hand and the Neoplatonism of Plotinus on the other, thus bridging a gap of more than 500 years.
After having thus shown the outlines of Plotinus' philosophy and the means of transmission of Platonic thought throughout the ages, Halfwassen exemplifies in the last two chapters of his book his theory of the innate resemblance between Platonism and Neoplatonism by analyzing two key passages of the Platonic oeuvre.
First, he analyses Platonic henology as presented in the Republic (220-264). Above all, it is the Analogy of the Sun (Rep. 506b-509c) that represents the ontological key-passage of Plato's work. This megiston mathêma symbolizes the absolute transcendence of the principle of the One, which surpasses cognition, but whose existence is an unavoidable necessity of mind, to which it gives the light of perception through the idea of Oneness. However, absolute Oneness must transcend even existence and oneness itself, because each attribute tends to define absolute Oneness and therefore reduce it to a plural structure: "Denn Sein bedeutet wesenhaft Bestimmtheit und ist damit schon eine Zweiheit: es läßt sich auseinanderlegen in etwas und das, was es ist [...]." (p. 260) Therefore, Plato makes the distinction between an absolute and a non-absolute One, just as Plotinus will later.
The absolute One is omnitranscendent and, just as the Sun cannot be seen adequately with the naked eye, it cannot be understood directly, but can only be approached through a negative theology. The non-absolute oneness on the other hand includes the principle of existence, cognition and the intelligible Ideas and, like the light of the sun, is the necessary intermediate between the absolute One and the Plurality: "Wahrheit [...] und Wissen [...] aber sind Weisen der Einheit in der Vielheit, in denen sich das absolute Eine manifestiert wie die Sonne in dem von ihr ausstrahlenden Licht." (p. 253) "Sowenig aber das Licht oder das Sehen selbst die Sonne ist, sowenig ist die Wahrheit oder das Wissen selbst das Gute und das Eine selbst; beide verdanken ihre vereinigende Kraft vielmehr einem jenseitigen Ursprung. [...] Das Gute selbst, das als Prinzip der Einheit von Sein und Denken Wahrheit und Wissen allererst ermöglicht, ist darum nicht mit ihnen identisch, sondern liegt notwendig als reine absolute Einheit über sie beide hinaus." (p. 257)
In the next chapter, Halfwassen gives a very detailed interpretation and exegesis of the first hypothesis of Plato's famous Parmenides (pp. 265-405), while constantly referring to the general argument of the dialogue.
Halfwassen first explains that the startling aporiai and contradictions of the Parmenides brought about the emergence of four schools of interpretation (pp. 265-298). Whereas the first one defines the dialogue as anti-eleatic irony, and the second one as simple exercise in logic without metaphysical aspirations, the third mainly understands the Parmenides as a lesson in ontology of whose apparently contradictory teachings only one can be true. The fourth school finally sees the dialogue as a hint of Plato's unwritten doctrine, in which the apparent contradictions are only due to the logical laws of different levels of existence, which therefore rather support each other instead of contradicting each other.
Halfwassen himself, trying to demonstrate the truth of the last assumption, starts his analysis from the main results of his detailed commentary on the Republic: the absolute transcendence of the One, the obvious existence of an undefined Plurality, and the necessity of a non-absolute Oneness which also comprises the world of logic and ideas. Halfwassen tries to show that each one of these three ontological categories forms the basis of one of the (apparently contradicting) three hypotheses of the Parmenides. These are respectively based on different accentuations of the assumption, "that the Oneness exists". The first stresses the Oneness (Parm. 137c-142a), from which it follows that the absolute transcendence of the Oneness even has to surpass existence itself. The second puts the accent on the existence (142b-155e) and implies necessarily a plurality of attributes of the One and hence its non-existence. The third gives equal importance to each word (155e-157b) and from it deduces the existence of a principle of the One, uniting absolute Oneness and Plurality, but being limited in its extent.
Having thus demonstrated the parallels between the Republic and the Parmenides and their concordance with the teachings of Plotinus, he argues that Plotinus merely systematized the unwritten doctrine of Plato, and shaped Neoplatonism as a more accurate continuation of the Old Academy than the Middle or New Academies had been. Halfwassen then concludes his study with a general observation on the cognitive importance of the negative theology: "Die Negation ist derjenige Akt des transzendierenden Denkens, in dem dieses im wissenden Nichtwissen die Grenze erfährt, die es als Denken nicht übersteigen kann. Diese Grenze ist das Mysterium der absoluten Transzendenz, dem das Denken nur entspricht, indem es sich in der Negation der Negation selbst übersteigt und so zur Aufhebung bringt. [...] Hinausgehoben über sich selbst, wird es in der Erleuchtung durch das überhelle Licht des Einen selbst mit diesem eins." (p. 405)
There is not much to say in criticism of Halfwassen's general thesis. The major observation has to be, of course, that the whole study is based on the assumption of the existence of Plato's unwritten, esoteric doctrine. If the reader is not willing to accept this premise, the structure of the whole work becomes nearly obsolete. If the premise is accepted -- which is the case with the present reviewer -- then Halfwassen's study gives unquestionable evidence of the profound similarities between (esoteric) Platonism, as reconstructed from the fragments of Aristotle and Speusippus and the esoteric interpretation of the Parmenides and the Republic, and Neoplatonism. It thereby proves that Plotinus' teachings have to be taken as a rather accurate, if only sometimes systematizing rendering of Plato's original thought -- a proof that will certainly end the numerous attempts at considering Neoplatonism as an inadequate source for the understanding and reconstruction of Platonism.
The fact that the central ontological dialogues of Plato cannot be understood without an exterior interpretation, based on the esoteric doctrine, from which only fragments survived, implies the impossibility of proving the continuity between Plato and Plotinus without basing the chapters on Plato on assumptions exterior to the extant works. To solve this methodological problem and to avoid the risk of explaining the continuity between Platonism and Neoplatonism only through the evidence of Aristotle and Speusippus, Halfwassen ingeniously decided to prove this continuity by turning his book in a certain way upside down: It starts with the rather conclusive thesis, then depicts Plotinus' philosophy, and afterwards describes the transmission of Platonic thought from the Ancient Academy to Plotinus - a chapter which is persuasive, but somewhat short, and which could have been more extensive in dealing with Platonic influences in Stoic, Christian and Neopythagorean philosophy. Only then does Halfwassen analyze the Analogy of the Sun as found in the Republic, interpret it through the Parmenides, and then finally investigate the Parmenides itself as the main evidence for the Metaphysics of the One in the works of Plato. This structure is, of course, necessary in order to prove the "Platonism of Neoplatonism" without starting the line of argument directly with problematic interpretations of the esoteric doctrine itself. However, it may strike the reader as being rather unusual.
Another observation, this one perhaps somewhat more problematic, is that Halfwassen's study, in its argumentative structure, sometimes oscillates between different scientific genres. On the one hand, his declared aim is to prove the philosophical continuity between Plato and Plotinus. But on the other hand, far from being only a philological and philosophical comparison between the fragmentary evidence of Plato's esoteric doctrine and Plotinus' main writings, Halfwassen's study is much more of an imaginative reconstruction of an ideal philosophical synthesis of Plato and Plotinus. This implies that Halfwassen sometimes seems more occupied with explaining Plato through Plotinus and vice versa and even analyzing the Republic through the Parmenides and the reverse than with sticking to the subject itself and accepting a more fragmentary and text-immanent interpretation.
However, even if this approach to the subject seems more reconstructive and speculative than a simple philological comparison would have been, the reviewer has to admit that he cannot but accept the vast majority of Halfwassen's parallels between Plato and Plotinus, and thereby considers the methodology of Halfwassen as justified by the results achieved. Nevertheless, from a methodological point of view, "Der Aufstieg zum Einen" is much more a justification and construction of a personal Platonic/Neoplatonic synthesis than an impersonal, fragmentary and empirical comparison of loci classici.
The only problem that arises from merging the philological and historical side of philosophy with a concurrent personal attempt to justify the ontology of the synthesis so obtained is that the reasoning is sometimes anachronistic. Halfwassen prudently restrains himself to a mere rendering of classic analogies and logical figures and only occasionally refers to modern philosophers such as Fichte, Schelling and Hegel, thereby staying within the usual instrumentarium of philology. But it can be felt between the lines that he himself considers (Neo)Platonism as still absolutely valid today and does a good deal of synthesizing work himself. His suggestions seem fairly reasonable,2 but would have been still more persuasive if Halfwassen had tried to show the validity of Platonism and Neoplatonism in the light of recent philosophical research instead of restraining himself to underlining the validity of classical and sometimes somewhat obsolete argumentative figures. In the same way, the references to modern philosophy are rather cursory and tend only to justify or to contrast some of the basic assumptions of (Neo)Platonism, but never to start a real intertextual discourse or to prove the validity of the "Philosophy of the One" with modern methods -- an undertaking that would of course have surpassed the declared historical aim of the study and verged on the sketching of a new, contemporaneous Neoplatonism.
Finally, it has to be mentioned for non-German readers that the reading of Halfwassen's book can be, for those perhaps not accustomed to the specific vocabulary of German ontological speculations, somewhat difficult (and tedious), because the author often plays with the accentuation of the different sentences. "Durch die Teilhabe an dem überseienden Einen empfängt alles Seiende Einheit und Bestimmtheit [...]; denn was nicht Eines ist, das ist überhaupt nicht, sondern zergeht als grenzenlos Vieles ins Nichts. Darum ist das Seiende nur, sofern es Eines ist; es ist seiend darum, weil es Eines ist: durch seine Einheit ist es vom Nichtsein abgehoben und zum Sein bestimmt." (p. 259). This is a good example of what awaits the reader in large parts of the book, which is written in a clear and consequent, but sometimes very accentuated language.
All of these observations have more to do with the methodological approach of Halfwassen's book and the problems inherent in a synthesis of historical reconstruction and personal justification; they do not touch the inner essence of Halfwassen's masterly work. Rarely have the similarities between Platonism and Neoplatonism been summarized and presented in such a clear, concise and strictly logical way; seldom, I daresay, has the Analogy of the Sun been explained in such a profound and clear manner. The numerous apparent contradictions of the Parmenides have been resolved in an elegant and consistent fashion rarely seen before, while the many aspects and problems of henological philosophy never cause the author to lose sight of his general structural approach. Halfwassen's "Der Aufstieg zum Einen" ought to become a standard book for a new generation of scholarly research in the field of esoteric Platonism, as well as the field of Neoplatonism. The only regret the reviewer has to signal is that out of this synthesis of Platonism and Neoplatonism the author has not yet produced a personal henological system of philosophy, based on modern philosophical premises.
1. Gaiser, K., Platons ungeschriebene Lehre, Stuttgart 1963.
2. cf. Vittorio Hösle, Wahrheit und Geschichte, Stuttgart-Bad Canstatt 1984, who shows that the history of philosophy is a repetition of parallel dialectical cycles, each one ending with idealistic philosophies such as Plato, Plotinus, Cusanus and Hegel.