In addition to Marsilio Ficino's Platonic Theology and his comments on Plato, the I Tatti Renaissance Library now publishes Ficino's introductory treatises to the books of Plotinus's Enneads. They document his late philosophy and frequently revisit his previously held theories. The present Latin-English edition regards Ennead III, books 1–4. The chapters on book 1 deal with fate in relation to the human soul and fatal necessity, books 2–3 address providence in the order of the world, and book 4 centers on demons.

This edition could well enlarge the canon of sources available to philosophers and researchers of Renaissance thought. Unfortunately, the translation is not reliable, due to errors, unfortunate choices, and problems of interpretation. Here are a few examples: On pages 18–19, “in qua residet actus” is translated as “in which it [activity] comes to rest.” A more accurate rendering would read, “resides,” for it does not stop. On pages 22–23, “revolutionem caelestium esse rerum principium … et fatum” is translated as “the celestial revolution and fate is the causal principle of things.” But Ficino gives a definition of fate: “the revolution of the heavens is the principle and fate.” On pages 28–29, “munus ad agendum proprium” is translated as “the gift of acting in the proper sense,” but a more accurate formulation would be “of its own acting”—this is not about semantics of action. On pages 30–31, “[motor intellectualis] non sit pars universi sed ipse in se aliquod universum” becomes “[intellectual mover] is not itself a part of the universe but something universal in itself”; rather, the intellect is “not part of the universe but itself and in itself a universe.” On pages 92–93, translating “consuetudinem ipsam alteram esse naturam” as “habit is … an alternative nature” conceals the common place of “second nature” (Cicero, De finibus 5.74) and implies some sort of choice. The next sentence states that consuetudo is not fixed but develops: “non … necessitate constare sed … provenire” becomes “habit is established not by … necessity but comes about.” “Is established” misses the point, however; “consists of” would be correct. On pages 266–67, “libentius” is rendered as “more freely” instead of “preferably” or “prefers to.” In book 4, Ficino argues against the transmigration of souls, saying (300–02) it is not the case that bad people have no human mind—which makes it so that their souls can move into animal bodies—they are simply distracted by senses and fancies: “Non enim rationis acumen otium penitus agit in pravis, immo negotiatur assidue, quamvis circa spectacula sensus et imaginationis obiecta vel comparand[a] vel devitanda plurimum diversetur.” The translation reads, “For among wicked people the acuity of reason never acts quietly within. On the contrary it is constantly involved in business, as though going far out of its way to either attain or evade the sights of sense and the objects of imagination.” The segments in italics would be better phrased as “does not idle wholly” and “albeit distracted in order to.” These are some of the errors. One may ask whether it helps the reader to translate Latin simpliciter consistently with “simpliciter” (passim), or adventitius with “adventitious” (18–19). But to see influxus translated as “emanation[s]” (32–33, 66–67, 72–73) is surprising, especially in a Neoplatonic context. Ficino argues about astrology, and “influxus” means the influence of stars on earthly bodies—“influence” being the term of art. “Emanation” does not belong to astrology; rather, it denotes the “outflow” of the lower hypostases from the One, a staple of Neoplatonic metaphysics. Indeed, the translator uses the terms “emanative continuity” and “emanate” in this metaphysical meaning (xxx, xxxvii, clxii). A problem of interpretation arises on the very first pages: Ficino establishes the Platonist principle that in the eternal, being is act and act is being. The translation always renders “actio est esse” as “action is its being” (16–18, 17–19), leaving open to what “its” is referring.

Stephen Gersh added an “Analytical Study” of over two hundred pages, which discusses the relation between Plotinus's and Ficino's thought. It is not an introduction for beginners, and would deserve publication as a separate monograph, followed by a separate review.