St. Bonaventure's Arguments Against the Eternity of the World Fail

The question of whether or not the world is past eternal is an old philosophical question, which, in the modern scientific age, has an empirical element to it because of Big Bang cosmology (NASA, “The Big Bang”, 1). There have been many arguments for the finitude of the past dating from at least the time of Al-Ghazali, but have stretched into the present with figures like Alexander Pruss formulating novel arguments for this view based on set theory (Griffel, “Al-Ghazali”, 1; Pruss, “Causal Finitism and the Kalaam Argument”, 7-9). Moreover, contemporary discussions around cosmological arguments for God’s existence, particularly the kalam cosmological argument, involve rich philosophical discussions about the temporal finitude of the past (Reichenbach, “Cosmological Argument”, 1). 

Despite the lively discussion around this topic in contemporary analytic philosophy, the medieval debate around this same issue is almost always ignored by philosophers today, even though there are many points in the medieval debate which could be helpful for contemporary discussions. In particular, St. Bonaventure presented powerful arguments both for the infinitude of the past and against the finitude of it, while still maintaining the finitude of the past. These arguments center around the nature of causation and how they relate to change and time. In Vollert’s collection of medieval works on the subject, one can find a good summary of his arguments on page 105, and these arguments are the focus of this essay. In this work, there is one argument for the eternity of the past and one against the finitude of the past, which are rooted in Aristotelian metaphysics, that Bonaventure presents, both of which will be discussed below. Then St. Bonaventure’s arguments for the finitude of the past will be explored. Ultimately, St. Bonaventure’s argument for the finitude of the past, should not be viewed as definitive because per se causation occurs atemporally and is the way in which God relates to creation.

Firstly, it is worth exploring the argument for the eternity of the past which St. Bonaventure later refutes. Here is the relevant text:

Before every motion and change, there is the motion of the first movable thing (primm mobile); but everything which begins to be begins by way of motion or change; therefore that motion (viz,. Of that first movable thing) is before all that which begins to be. But that motion could not have preceded itself or its moveable thing (mobile); therefore it could not possibly have a beginning. (Vollert, On the Eternity of the World, 105)

This argument relies on Aristotelian metaphysics in several ways. Firstly, it assumes the Aristotelian position that time is the measure of change and so is ontologically posterior to change (Shields, “Aristotle”, 1). Moreover, the argument employs a per accidens notion of Aristotelian causation, which is a causal series spread out over time, which is very important in order to understand St. Bonaventure’s argument for the finitude of the past (Knuuttila, “Medieval Theories of Modality”, 1). Given this, it is clear why these things could preclude the finitude of the past. There will be a first member in the causal series of creation, which, when caused to exist, cannot undergo change because it does not move from potency to act as other members of the series do, but, rather, comes to be as a whole matter-form composite, which means that it is not changed when it comes into existence. If it is not changed when it comes into existence, and given that time is the measure of change, since there is no change when it comes into being its coming into existence does not occur in time. So, the world then does not have a beginning in time and must be eternal. This is an interesting argument for the eternity of the past and a similar logic can be found in Aquinas’s analysis of God’s relation to creation, which will be explored later.

Moving on from this is his presentation of the inverse of the argument above:

Everything which comes to be comes to be through motion or change; consequently, if motion comes to be it comes to be through motion or change, and with regard to this latter motion the question is similarly raised. Therefore, either there is to be an infinite regress or a positing of some motion lacking a beginning; if the motion, then also the moveable thing and, consequently, also the world. (Vollert, On the Eternity of the World, 105)

As noted above, this is merely an inversion of the previous argument and assumes that there is a first instigator of motion in the world, which is derived from the fact that infinite regresses are impossible. The key idea in this version of the argument is that all things come to be through motion or change, which, again, is a very Aristotelian idea. Since there must be an instigator of motion, and all things that come to be come to be through motion or change, the first mover in the world must not have been moved itself. Thus, the world itself must have not undergone change or motion when it came to be and so must be eternal. The central idea to this argument, which is that whatever comes to be comes to be through motion or change, is one which will be augmented by Aquinas, which enables him to avoid determining whether or not the world had a beginning. Bonaventure provides four other arguments for the eternity of the past and responds to each one of these arguments as well, but these arguments and responses will not be discussed because they go beyond the scope of this essay.

With that in place, we can move onto look at the most potent of St. Bonaventure’s arguments for the finitude of the past is shown here:

It is impossible for that which has being after non-being to have eternal being, because this implies a contradiction. But the world has being after non-being. Therefore it is impossible that it be eternal. That it has being after non-being is proven as follows: everything whose having of being is totally from another is produced by the latter out of nothing; but the world has its being totally from God; therefore the world is out of nothing. But not out of nothing as a matter (materitaltier); therefore out of nothing as an origin (originaliter). It is evident that everything which is totally produced by something differing in essence has being out of nothing. For what is totally produced is produced in its matter and form. But matter does not have that out of which it would be produced because it is out of God (ex Deo). Clearly, then, it is out of nothing. (Vollert, On the Eternity of the World, 109)

It should first be noted that before this argument, Bonaventure provides five other arguments for the finitude of the past mostly from contradictions and queries which arise from there being an infinite number of things in reality. However, the argument above is, in my view, the most powerful argument he presents for the finitude of the past and also the one which is least explored in contemporary discussions, which is why I would like to focus on it (Reichenbach, “Cosmological Argument”, 1). 

Now, in assessing the argument, the first thing to note is that there is a linking between something being contingent and being temporal, as beings which have beings after being in a state of non-being are contingent things. It states that contingent beings are, by definition, not eternal beings. What this results in is that because the world is contingent, Bonaventure concludes that the world must also not be temporal. The rest of the section listed above is just him defining what he means by non-being and proving that the world came out of non-being, in order to support his first premise.

The argument is interesting, but I believe that St. Thomas Aquinas offers some ideas that render St. Bonaventure’s argument to be non-demonstrative. In his De Ente et Essentia, Aquinas provides an argument for God’s existence from the fact that there are essence-esse composites in reality. What is crucial here is to understand that he says that the relationship between essence and esse is like the relationship between potency and act where essence stands in potentiality to esse (Kerr, Aquinas’s Way to God, 13). Moreover, the argument says that in creation, essence-esse composites receive their esse from God Himself through per se causation, which is an atemporal form of causation, or at least it can be. The argument is rather powerful because things which have essence, which is finite definitional content, must have their esse given to them from without. Otherwise, essence includes esse, there is vicious circularity in this view where essence depends on esse for its being, but esse is posterior to essence and so depends on essence for its being. Moreover, esse cannot be located within a per accidens causal chain because the same problem would arise. Thus, esse must be located within a per se causal chain and so God’s causal relationship to the world is a per se one.

What this means for Bonaventure’s argument, though, is that God creates the world through an atemporal causal relationship, which makes it impossible for us to see whether or not the world was created in time because the relationship between God and the world is atemporal. Thus, Bonaventure’s argument for the finitude of the past is non-demonstrative because it does not account for the fact that God relates to the world through per se causation.

In conclusion, the philosophical debate surrounding the finitude or eternity of the past is a debate which has raged on from at least the Islamic golden age and continues in the present day. St. Bonaventure, in the middle ages, presented at least six interesting arguments for the finitude of the past, the most potent of which is argument from the fact that the world is created ex nihilo, out of nothing. While the argument is interesting and almost persuasive, I do not think it should be viewed as definitively proving the finitude of the past because St. Thomas Aquinas provides a good argument for God’s existence where God causes the world through per se causation, which allows for the possibility of the world being eternal. Moreover, the argument that St. Bonaventure provides, and the ones he responds to as well, seem to be operating in a way which assumes that God relates to the world through per accidens causation. Thus, merely from looking at St. Bonaventure’s argument alone, we do not have a basis for concluding that the world is not eternal. This fact should spur novel philosophical inquiry as proving that the past is finite would help support kalam cosmological arguments, thus offering another philosophical path to God.

Works Cited

Griffel, Frank. “Al-Ghazali.” Stanford Encyclopedia of Philosophy, Stanford University, 8 May 2020, plato.stanford.edu/entries/al-ghazali/.

NASA.“The Big Bang.”, NASA, July 2023, science.nasa.gov/astrophysics/focus-areas/what-powered-the-big-bang/.

Kerr, Gaven. Aquinas’s Way to God: The Proof in De Ente et Essentia. Oxford University Press, 2015.

Knuuttila, Simo. “Medieval Theories of Modality.” Stanford Encyclopedia of Philosophy, Stanford University, 15 Apr. 2021, plato.stanford.edu/entries/modality-medieval/.

Pruss, Alexander. “Causal Finitism and the Kalaam Argument.” Alexander Pruss, Baylor University, 2022, alexanderpruss.com/papers/kalaam.pdf.

Reichenbach, Bruce. “Cosmological Argument.” Stanford Encyclopedia of Philosophy, Stanford University, 30 June 2022, plato.stanford.edu/entries/cosmological-argument/.

Vollert, Cyril, et al. On the Eternity of the World (De Aeternitate Mundi) in St. Thomas of Aquinas, Siger of Brabant, St. Bonaventure. Marquette University Press, 1964.

Shields, Christopher. “Aristotle.” Stanford Encyclopedia of Philosophy, Stanford University, 25 Aug. 2020, plato.stanford.edu/entries/aristotle/.