As today is St. Bonaventure's day, I give here a re-post from 2013.
Today is the Feast of St. Bonaventure, Doctor of the Church. He is usually known as the Seraphic Doctor, but his older designation was Doctor Devotus, the Devout Doctor. The name 'Bonaventure' may itself be a nickname; it means 'Good Fortune' and is said to have been given to him by St. Francis of Assisi, albeit by a late legend. His given name was Giovanni di Fidanza. His two most important works are the Breviloquium, which is a brilliant summary of the Catholic faith, and the Itinerarium, the Journey of the Mind to God, which is a brief, very dense work full of good things.
The Itinerarium is a meditation on the Crucified Seraph seen by St. Francis of Assisi at La Verna when he received the stigmata. Bonaventure had been the Minister General of the Franciscan order for two years by this point, and it was the thirty-third anniversary of the vision. Bonaventure pictures the six-winged seraph as representing the ascent of the mind to God, each wing representing another step. The key theme of the work is that of speculatio, which in this context means 'contemplation', but is closely connected to the word speculum, which is the word for 'mirror'. Each step in the ascent is a way we find things mirroring God. Each pair of wings is divided into a way in which we see God through the mirror of things and a higher way in which we see God in the mirror of things. To see God as through a mirror is to see him as that from which things come; to see God as in a mirror is to see him as actively working in the things that come from him. With the first and lowest pair of wings the mirror is the material world; with the next pair of wings, the mirror is our own souls; and with the third and highest pair of wings, the mirror is the divine name itself, first the name Being, then the name Good. Thence, of course, we pass over into God himself through the union of love.
Throughout this ascent, Bonaventure's governing principle is omnis effectus est signum causae, et exemplatum exemplaris, et via finis, ad quem ducit: "every effect is sign of its cause, and exemplate of its exemplar, and path to the end to which it leads" (2.12). Thus in the material world around us, recognizing it to be an effect requiring a cause or originating principle, we find the vestiges (vestigia: the word literally means 'footprints', but is usually translated as 'traces') of divine power (for things come from him as an effect), divine wisdom (for things imitate his understanding of them), and divine goodness (for things tend toward him as their universal good). This is reflected in a very great many ways:
weight or tendency, number or distinction, measure or limitation
as found in faith or belief
origin, course, terminus
as known in investigative reason
existing, living, knowing
One of the things that makes Bonaventure sometimes difficult to read, and certainly makes his theology difficult to convey, is his facility at thinking multidimensionally about whatever topic he is considering. Each triad noted above is a pattern reflecting the pattern of power, wisdom, goodness, and equally of causal sign, exemplification, way. But the three levels themselves also exhibit this pattern, so that the first triad, as a triad, is a sign of divine power; the second triad, as a triad, is an exemplification of divine wisdom; and the third triad, as a triad, exhibits a path of ascent to divine goodness. Further, the whole series reiterates the three pairs of wings of the seraph and thus the three stages of ascent: the first triad suggests the material world in itself; the second triad, while remaining at the level of the material world, introduces a suggestion of the human mind; and the third triad, while again remaining at the level of the material world, introduces a suggestion of something higher than our own minds because on the basis of this triad the mind can build three kinds of inferences to things more noble than itself. Further, the first triad gives the intrinsic character of that which is contemplated at the first wing of the seraph; the second triad is suggestive of what is contemplated at the second wing of the seraph; and the third triad is suggestive of what is contemplated at the third wing of the seraph. Thus the triads reflect the structure of the work as well as reflecting each other. And we, in knowing the material world, reflect the triads, in whose reflection we see the divine power, wisdom, and goodness. This is not even getting into the fact that there are seven ways in which these triads reflect God's power, wisdom, and goodness -- origin, magnitude, multitude, beauty, plenitude, activity, order -- each of which is analyzable into a triad, and this triad is, depending on which of the three ways we look at it, one of the three triads above with respect to that particular property of creatures.
The second wing concerns the material world as sensible (and we have opinion or belief rather than rigorous knowledge about the material world precisely as sensible); it is the world as macrocosm ingressing, so to speak, into the mind as microcosm through the senses. Recognizing that everything that is moved is moved by another, we recognize in sensation itself the need for a higher cause of some kind. In each sensation we find an apprehension, a delight or fulfillment of our sensory capacities deriving from this apprehension, and a judgment about what we sense deriving from them both. At each level of sensation we have a suggestion of something divine: the first, in which we apprehend objects through their similitudes in the medium connecting them and us, gives us some recognition of the possibility of divine emanation through which we may know God; the second, in which we are pleased or fulfilled by this apprehension arising from the harmony of the object with our ability to sense them, we have some recognition of the possibility of divine harmony through which we may delight in God; and in the third, in which we abstract from sensible things their changeableness, we have some recognition of divine eternity and immutability. At the sensible level we are most familiar with the quantitative character of the world, and Bonaventure draws on Augustine to identify seven kinds of 'number', which is (you will recall from above) associated with distinction, and thus seven kinds of distinctions in the sensible world, through which we can rise to their exemplar in divine wisdom. And divine wisdom, again, is the second member of the triad of divine attributes reflected by creaturely effects, which goes with the fact that we are considering the second wing of the seraph.
I am simplifying all of this somewhat; there are intricate interrelations I haven't mentioned. And all this occurs in the space of about ten to twenty pages. No other Christian theologian in the history of the Church can seriously rival Bonaventure's capacity for stating his full position with succinctness and concision. His ability to concentrate an extensive chain of reasoning into a few sentences by means of list and analogy is sometimes dizzying. But it is not mere game-playing. It is all very well thought out; he can justify by argument every single one of these reflections of reflections of reflections, and does, sometimes in the Itinerarium itself (although these arguments are stated with the same kind of super-concision) and usually also elsewhere. Bonaventure, even at his most readable (as in his Tree of Life, which is about the life of Christ, or his Legenda maior, which is his official life of St. Francis for the Franciscan order) cannot really be read; he must be unpacked, unspooled, unzipped. Just as in Aquinas we generally get theological reasoning in a form that begins to approach maximal usefulness as a pedagogical reference point for further discussion, what we generally get with Bonaventure is theological reasoning in a form approaching its maximal degree of concentrated conciseness. At least, nobody has ever been able to come up with a more concentrated form. It is a bit much for the mind to take in at once. But by thinking through Bonaventure closely you can always, always, learn a new way to see the world, one you hadn't thought of before.