Introduction by Wendy Boring

Bonaventure says: “Material cause is suggested by the name of rivers in the plural, not in the singular, so that not only the material of the whole book or the subject in general be touched upon, but also the material of particular books in specific. On account of noting this, that next to the fourfold property of a material river, the spiritual river is fourfold, concerning which, according to the fourfold difference there are four books of Sententiae. For in fact, I consider the material river as far as duration, and I find perpetuity. For just as Isidorus says: "A river is perpetual flow." I consider as much as to its extension, and I find spaciousness. For in this, a river is distinguished from a brook. I consider as much as to movement, and I find circulation. For so it is said in the first book of Ecclesiastes: They are turned back to the place whence rivers go out, etc. I consider the effect, and I find a thorough cleansing. For a river cleanses the earth, through which it runs, on account of the abundance of its waters, and so because it is not defiled. And since all the transferrers transfer according to some likeness, from this fourfold condition the metaphor is taken, [and] a fourfold river is found in spiritual matters, just as we can gather from Scripture. ”

Original Latin

Four Rivers of Eden

Medieval writings on the four rivers of Creation were a case in which biblical authority met shaky geography. In Bonaventure's day, medieval thinkers following Genesis 2:8, 10-14, described the four great rivers of their world - the Tigris, Euphrates, Gihon (Nile), Phison (usually identified with the Ganges) - as having their source in the Garden of Eden.

Although the actual, physical location of Eden was debated, or confessed as a mystery, tradition had it that the four rivers could run underground from wherever Eden might be, and emerge in different locations around the world.

Four Symbols of Faith

Bonaventure gives a metaphorical reading of the Genesis text that allows him to mine the suggestive nature of the water metaphors. The four rivers of Creation are symbolic of the mysteries of faith.

• The first river symbolizes the eternally flowing Godhead
• The second is a symbol for creation, which is as wide and deep as the sea
• The third represents the Incarnation, Christ flowing out of the Godhead and back into God ["as in a circle, the last joins itself onto the first, so in the Incarnation the highest joins itself on to the lowest, God unites himself with clay"]
• The fourth is the sacraments that stream from Christ.

Here Bonaventure equates the water of the fourth river with the blood of Christ. He draws on both the life-giving and the flowing nature of water and blood: "the water of life, clear as crystal, that went forth from the throne of God and of the Lamb," for "from the side of Christ as he slept flowed out the sacraments, as water and blood streamed out."

Four Hidden Things of Revelation

Bonaventure's proemium to the Commentary on the Sentences emphasizes the depth of the mysteries of Scripture, which are as unfathomable as the sea. The Commentary, he says, will deal with the revelatio quattuor absconditorum, the four hidden things of revelation:

• the greatness of the divine being
• the dispensation of divine wisdom
• the strength of the divine power
• the sweetness of the divine mercy.

The metaphors of water capture beautifully the paradox of revelation: it is hidden yet revealed, with a depth like the ocean, never plumbed, yet crystal clear.

As Bonaventure will go on to assert in a later text, our rational investigations can never plumb the depths of the mysteries of God: “Like a drop that one takes from the sea, so are all the theoriae that are produced when compared with those that could be produced” (Hexaermeon, 13, 1-6; V 388ab).