Project Description

The project identifies three major conceptual changes that took place in the early fourteenth century and which all are crucial for the mechanical philosophers of the seventeenth century. The first of these is the concept of power or activity, the second is the concepts of substance and quantity, and finally the concepts of natural laws and teleology. Given the remarkable similarities between Ockham and Buridan and later early modern thinkers like Descartes, the project assumes that this is not a coincidence and wants to trace the historical developments of these ideas from the fourteenth to the seventeenth century. The project hence naturally divides into a conceptual part, explaining and developing the conceptual similarities between Ockham and Buridan on the one hand and Descartes on the other, and a historical part devoted to filling in the historical gap between these thinkers.

The early fourteenth century including Ockham and Buridan are fairly well studied, but the time period in the scholastic tradition between 1350 and 1600 is very little studied and scholars know hardly anything about the development of the ideas and concepts of concerns for this project during this period. There are a number of thinkers of particularly interest in bridging the gap between Ockham and Descartes. The project will look at a number of them including Marsilius of Inghen (late fourteenth), Nicole Oresme (late fourteenth), Pierre d’Ailly (late fourteenth), Paul of Venice (early fifteenth), Gabriel Biel (mid fifteenth century), Jodocus Trutfetter (late fifteenth), John Mair (early sixteenth), Jacopo Zabarella (mid sixteenth), and Francesco Suarez (late sixteenth). It will also study a number of different works by these thinkers including commentaries on Aristotle’s Physics, On generation and corruption and On the heavens, as well as other philosophical works. The project will in particular study John Mair and the students surrounding him in 1500 Paris. Paris University was the main intellectual center in Europe at that time and Mair was the foremost philosopher of the time. He was extremely influential and his students all studied and edited works by Ockham and Buridan. The list of his students is very impressive and includes for example Ignatius of Loyola, the founder of the Jesuit order. There is hence a direct link through Mair via Jesuit thinkers like Suarez between the ideas of Ockham and Buridan and Descartes. This connection has never been studied before.

A very similar view of nature was developed by Ockham in the early fourteenth century. He wanted in general to reduce his ontological commitments and as part of this he eliminated powers from the categories of things existing in the world. He took his starting point from his predecessor John Duns Scotus’s distinction between natural and rational powers. Ockham claimed that there are no natural powers in nature that arise from nature itself. All power is placed there by God or some other active power like the human mind, and hence a thing, on his view, is just its powers. Hence making a fire is making a tendency to burn. Ockham is also like Descartes a dualist about mind and body, and hence he thinks that power or activity is solely in the mind. This is the will on his view and it is what he calls a rational power. The elimination of powers from all natural substances is of absolute importance for the development of a modern view of nature. This project will trace the discussion of power up to Descartes.

Substance and Quantity

Nominalist Mereology

The fourteenth century saw some radical changes in the way substance was conceptualized. Ockham challenged the Thomistic way of thinking about it in the course of his systematic rethinking of metaphysics. According to Aquinas, a substance had no parts that are prior to it. A composite substance, an animal or a human being for example, comes to be out of another substance, but only what they call prime matter remains the same during this generative process and it has no existence on its own (per se existence). Since matter is their principle of individuation, form can have no existence before its union with matter. Hence nothing in an individual composite substance pre-exists its existence in nature. Two metaphysical theses are of crucial importance for understanding the changes in the concept of a substance that take place with Ockham :

i. A whole is nothing but its parts.

ii. All parts of an actual thing are themselves actual and their actuality is not derived from the whole.

Ockham insists that a substance is nothing but the parts that make it up. This is contrary to Aquinas who held that although substances have integral parts these parts depend ontologically on the whole of which they are parts. Each part of a substance is actual and not dependent on anything to make them actual, Ockham argues contrary to Aquinas. Every substantial form in nature (other than the human intellectual soul) is extended and composed of parts, according to Ockham. Hence all the properties of the whole form are going to be derivative upon its parts and furthermore all the properties of the whole composite substance will be derivative of the properties of the parts of the form and the matter. Since the integral parts of the form parallel exactly the integral parts of the matter, and since the matter is something existing in its own right, the view defended by Ockham is a fraction away from the abolition of the whole distinction between form and matter. This view appears quite similar to the later seventeenth century view of substance wherein the properties of the parts of the material body are all properties which have the actual material parts of the composite as their subjects. These radical implications of Ockham’s metaphysics were debated and questioned by Buridan and a range of thinkers influenced by him, like Nicole Oresme, Pierre d’Ailly, and John Mair up to the sixteenth century. The proposed research project aims to clarify this debate. It will particularly look at the discussions in 1500 Paris around the leading thinker of the time, John Mair.

Atomism and Corpuscularism

This time and place is also interesting for other reasons since Ancient atomism through the newly discovered text by Lucretius, De rerum natura, had become known. The project will highlight how this influenced the debate of the time. In his metaphysics, Ockham tries very hard to reduce the Aristotelian categories to only substance and quality. Buridan immediately challenged this, even though he agreed that one should not postulate entities beyond necessity. Buridan argued, however, that such a postulate was necessary when it comes to quantity – extension and magnitude, must be separate entities. On Ockham’s view all extended things are simply their extensions. One of his arguments for this was that not even God could make an extension distinct from a substance. Buridan’s arguments to the contrary are all derived from physics. Buridan notes, for example, that a closed balloon containing air will resist compression. But what is it that does the resisting? It is not the matter, because the same matter can with another form have a much smaller volume. And it is not the substantial form, because if the air is cooled the same form occupies a smaller space. Hence it must be the extension or magnitude of air that resist compression.  As the debate between Ockham and Buridan was taken over by fourteenth and fifteenth century thinkers and it was gradually realized what a fundamental importance the concept of quality has in physical explanations generally. But much more needs to be explored to trace out the development of this trend and understand its impact on the seventeenth century’s rise of the mechanical philosophy.

Laws of Nature and Teleology

There is a debate about final causality before Ockham and Buridan where Avicenna, Averroes and Aquinas factor prominently. But Ockham and Buridan fundamentally reshaped the discussion and it’s their debate that affected future generations. Ockham made it very clear in his Quodlibetal Questions IV, q. 1, what he thinks final causality is.

“I claim that the causality of an end is nothing other than its being loved and desired efficaciously by an agent, so that the effect is brought about because of the thing that is loved.”

The object of someone’s love is the end of that person’s actions, which are caused efficaciously for the sake of that end. The efficient cause of someone’s action is the will, but the final cause is the object loved. He is very clear further on in the same Quodlibetal Question that there is no final causality in nature and draws a sharp distinction between free agents and natural agents. The final cause is in the mind and not in nature on this view. Buridan works out the details of Ockham’s suggestion. His rethinking of final causality is motivated by the very problem that Spinoza would highlight three hundred years later. Buridan argues that “every cause is naturally prior to the caused thing […] but the end is not naturally prior…”. The problem is thus how something that is posterior to its effect can be a cause. To do so it must act backwards in time, since causes are naturally thought about as that which brings something about. The argument that worries him most seems however to be the following. Take the traditional Aristotelian picture that the cause of the doctor’s prescription of a certain medicine is the health of the patient. By analogy, then, it must follow that the cause of God’s action of creation is the world being created. But this implies that things inferior to God are causes of His actions, which is clearly absurd. Buridan thus takes this to be a knock-down argument against final causality. So, Buridan suggests the following.

“It seems to me that everybody by a natural impulse, as if determined by nature, accepts that an end is the cause of our operations. For example, if you ask a little old lady why she goes to church or to the market, she will say to you that she goes for the sake of hearing a mass or for the sake of buying a tunic, and if you are asked why you go to school, you will reply: for the sake of learning. Claims accepted in this way by everyone should not be entirely dismissed, because nothing more plausible and accepted could be brought forward to prove the opposite, as Aristotle says in Ethics VII.” (Questions on the Physics , q. 7).

Intentions: Ends or Efficient Causes?

Buridan view is hence that when we use ends to explain our actions we must to be exact redescribe our actions. When the little old lady says that she goes to church to listen to mass, we must recast this in terms of her desire or intentions to hear mass. The same way with the university students – they desire or intend learning and this is why they go to university and attend lectures. On Buridan’s view the final cause is internal to us as our desire or reason for acting. On such a view the Spinozistic argument against final causality does not apply, however, since final causality has been reduced to efficient causality, or the desire or intention of the agent, which is an efficient cause of the movement of the will. This also, of course, takes care of the argument that seems to have worried Buridan the most, namely the argument that the world is the cause of God creating it. The world is not the cause of anything, since the world only exists as an intentional object in the mind of God and as such it is an efficient cause of God’s act of creation. (Lagerlund, H. (2010). ‘The Incompatibility of Efficient and Final Causality: A ‘New’ Mind- Body Problem’. British Journal for the History of Philosophy). One of the worries of Aristotelian inspired philosophers in the Middle Ages was that if there were no end in nature then one thing would follow another haphazardly. To this objection Buridan sounds much like the seventeenth-century mechanistic philosophers, namely that efficient causes are sufficient. The regularity according to which one judges whether a natural action turns out as it should is not the end, but the law according to which it is accomplished and according to which the same cause always yields, ceteris paribus, the same effect. (Des Chene, D. (1996). Physiologia. Natural Philosophy in Late Aristotelian and Cartesian Thought. Ithaca: Cornell University Press). The proposed project will trace the discussions of final causality in the fifteenth century and particular emphasis will be put on the circle of John Mair. It was through thinkers like Mair that the revolutionary ideas of Ockham and Buridan effected later thinkers and scientists.

The project combines an analytical method with a historical, that is, conceptual analysis and historical analysis. It aims to clarify certain historically given concepts and trace them through a certain period of time. It is looking to bridge medieval and early modern philosophy and provide historical explanations for the developments within philosophy and early science.