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A
Hi, I'm Peter Adamson, and you're listening to the History of Philosophy podcast brought to you with the support of the philosophy department at King's College London and the LMU in Munich. Online@historyofphilosophy.net Today's episode will be an interview about Malefranche and occasionalism with Steven Nadler, who is Viless research Professor and William H. May II professor of Philosophy at the University of Wisconsin, Madison. Hello, Steve.
B
Hello, Peter.
A
Thank you so much for coming on the podcast. It's great to have you on because you've written some of the best work on occasionalism. So you're the man to talk to about this. And I have an obvious first question. How would you define occasionalism?
B
All right, well, that's the easy question. Occasionalism is the philosophical position that natural objects, human bodies, inanimate bodies, natural objects have no true causal efficacy whatsoever. They are not true causes. Bodies do not bring about effects in other bodies. They don't cause motion in other bodies. Minds do not cause motion in bodies. Minds do not cause their own mental states. This would be the most thoroughgoing version of occasionalism. The only true causal agent, the entire universe, on this view, is God. It's called occasionalism because the contact of one body with another serves as an occasion for God to move the bodies in the appropriate ways. The damage to the skin of a human being is the occasion for God to cause a sensation of pain in that person's mind. My volition to raise my arm is the occasion for God to make the arm to rise. And my desire to imagine a unicorn or an elephant is the occasion for God to reveal to me the appropriate ideas. And so in all of these domains, body, body, mind, body, mind, and the mind alone, God is responsible for all causal activity. Now, that's the most thoroughgoing version of occasionalism. There are some philosophers in the 17th century who I would call partial occasionalists. They're occasionalists when it comes to body body relations, but they leave the human mind with its own causal capacities. There are others who think that the mind itself is without its own causal power, but they're willing to allow that. Bodies can move other bodies. It's just that the mind cannot move the body and the body cannot cause effects in the mind.
A
And longtime listeners to the podcast will realize that in addition to 17th century occasionalism, there are some older ideas, like back in the medieval period, that sound a little bit like this. And I guess the word occasionalism really was invented in the 17th century. Is that right?
B
The word occasionalism comes quite late. Leibniz was the first to refer to what he called the system of occasional causes. But I think the term occasionalism itself is even later than that. But you're absolutely right, there are precedents in medieval philosophy and especially medieval Arabic philosophy. I'm sure your listeners have heard your podcast on the Mutukalimun, the medieval Arabic theologians, and among them there were the Asharites, followers of Al Ashari, and most famous would be Al Ghazali. And Al Ghazali's view is that God is the only true causal agent. He doesn't use the vocabulary of occasionalism. But I think we can say that occasionalism really does originate among these Arabic theologians. And even Maimonides, the 12th century Jewish philosopher, recognizes them as having a very peculiar view about the nature of causal relations.
A
Is there a historical link there, do you think? So? Are some ideas somehow getting through from the Islamic world all the way down to someone like Malabanche?
B
It's possible. I've not found any direct links. One possible intermediary might be Nicholas of Otocort, a 14th century Latin philosopher, who I think can be read as at least holding the negative theses of occasionalism and perhaps also the positive thesis as well. But that's a good question. And I've not yet found any direct link. If anything, it might be through Maimonides, because there were Latin translations of Maimonides Guide to the Perplexed, where he explains the Asherite view and Maimonides Latin text was not just available, but possessed by some of these early modern thinkers. Leibniz, for example.
A
Yeah. For what it's worth, my suspicion about this is that you've got volunteerism and like. So in other words, everything is up to God, right? God's arbitrary will. You had voluntarism in the Islamic world and you've got voluntarism and scholasticism, and that's a kind of a parallel development and not necessarily a case of causal connection, so to speak. Yeah, we don't need to sort that out now. In any case, speaking of the genesis of occasionalism, there's a general conception about where it comes from or what motivated it in the first place, which is that it's supposed to somehow solve the mind body interaction problem. And in your work on occasionalism, you've cast significant doubt on this. Could you explain why did people think this in the first place? That it would have something to do with the mind body problem? And if that's not the explanation, what is the explanation for why the occasionalists like the idea.
B
Well, the mind body problem is a handy dandy explanation for why one might be an occasionalist. But it is a mischaracterization. In fact, it's very difficult to find in most of the 17th century occasionalists, and especially the Cartesians, any acknowledgement that there's a problem of mind body interaction that is what we call the heterogeneity problem. How could something immaterial cause effects in something material and vice versa? There are hints of this here and there, but it's difficult to see that as the main argument for occasionalism. It's, you know, the 17th century or early modern philosophy generally has all these myths. There's the rationalist empiricist distinction myth. And this myth about occasionalism is a very popular one. I think its source is Leibniz, even though Leibniz is clear, knows better. But when he presents his doctrine of pre established harmony, he presents it as the third alternative to accounting for mind body relations. The first alternative would be Cartesian interactionism, which he dismisses as ruled out. And then he says, well, the occasionalist Cartesians recognize that there was this problem within the Cartesian philosophy. And so they came up with occasionalism to solve the mind body problem. And Leibniz says, well, my own system of pre established harmony is much better because it doesn't involve what he calls constant miracles. But we know that Leibniz knew better because he's also quite aware that there are many other motivations for occasionalism than providing an ad hoc resolution of a mind body problem. You know, it's a theory of matter. The Cartesian theory of matter generates problems that require occasional solutions, issues in Cartesian physics, issues about the nature of causality itself. And then as perhaps we'll talk later in the case of Malvarh, there are theological principles as well.
A
Yeah. So the problem about one body exerting causation on another body, maybe we could just dwell on that for a second because I think that's in some ways almost the most counterintuitive. I think people can understand why there'd be a problem about how does an immaterial mind affect a body that does sound strange, or vice versa. But you know, one billiard ball hitting another billiard ball, what would be a better explanation of why the second billiard ball moves? What's the problem of explaining body interaction on Cartesianism?
B
Well, there's both a priori and a posteriori considerations. That is, they're both principled objections to bodies causing effects in other bodies. And then empirical Problems. The principled or a priori problems stem from the Cartesian conception of matter. And this is where you wouldn't find precedent, let's say in the medieval sources. The Cartesian conception of a body is that any physical body is just extension, that is pure spatiality, three dimensionality. And as such, a body can only have a limited range of properties, mobility, size, shape and divisibility. But all of those properties are passive capacities. A body can be divided, a body can be moved, it's figured, it has parts and so on. But extension, your spatiality is a purely passive phenomenon and therefore there's no room for Cartesian body to have an active power. And this constitutes a very significant critique of the old Aristotelian view. The Aristotelians insisted that in addition to the matter of a body, you also had its substantial form and other forms, and these forms were active powers. Once you get rid of that metaphysics, that Aristotelian metaphysics, and all you have left of a body is geometric space, it's incapable in principle of having an active causal power. That would be the principled objection, the empirical objection, and this foreshadows something Hume will say in the 18th century is, well, look at what happens when one billiard ball hits another billiard ball. You see the motion of the one, you witness their contact and you see that one ceases to move and the other starts to move. But that's all you see. You don't see causation, you don't see any active power, you don't see any efficacy. You just see, see a sequence of events. And as Hume pointed out, you can see the sequence of events as many times as you want. What you will not see is necessity. Right?
A
Oh, there I saw a glimpse of the causation. Yeah, that's not going to happen.
B
The little blue spark.
A
Now you've been saying several times or you've talked about the Cartesians and although people tend to associate occasionalism, especially with Malebranche, who we've just been discussing on the last couple of episodes, in earlier episodes I mentioned that the immediate followers of Descartes, So people like Coydemois and La Forge, I mentioned that they already anticipate the occasionalist theory. In fact, to be honest, I was drawing a lot on your work when I described their views.
B
Right.
A
And one thing that I actually found myself thinking when I was reading what you wrote about La Forge and other early Cartesians is, wait a minute, didn't they already figure out the whole thing? Like, is there even anything else left for Malebranche to do? Or is he just the one who got famous for describing a theory that they had already pretty much developed?
B
So La Forge's problem is that he died too early. He was born in 1632 and died in 1666, right after the publication of his own really original treatise. He had played a role in completing Descartes de l', homme, the treatise on man, and helped in its publication. But then immediately after that, he composed his own treatise on the human mind and then died. So as important as a work, this is, I think, in both establishing Cartesianism as the dominant philosophical paradigm of the 17th century. And it was very influential in its time. It just kind of disappeared, except for specialists in 17th century philosophy. So most people, if they've heard of La Forge at all, and most people have not, they think of him as a very minor Cartesian. But Malebranche would not really have become the Cartesian philosopher he was had he not discovered a copy of La Forge's edition of Descartes del Homme in a bookstall in Paris. And he said it was so exciting. It was in the 1660s, it brought palpitations to his heart. He had to find a bench to sit down. So I think La Forge really does deserve a lot of credit. Courmois also published the same year as La Forge's work, his own discourses on the mind and the body. And these also were rather influential, especially with Leibniz. Courement was a less orthodox Cartesian than La Forge. Cordemont was an atomist. He believed that there were some basic indivisible pieces of matter in empty space. In if you're an orthodox Cartesian, that's incoherent because the body, if it's just geometrical space and it's impossible to have space without body. La Forge was a much more faithful Cartesian and in fact he saw his philosophical project as one of both disseminating Descartes ideas, supplementing them, going in places where Descartes intended to go, but never got the chance to, and sometimes correcting Descartes. And my take on La Forge is that he believes that his occasionalism is a doctrine that Descartes, had it been presented to him, would have approved, but did not really himself go that far. Malebranche was influenced by both of these thinkers. And I think Malebranche's occasionalism does have its immediate sources, especially in the arguments that La Forge uses. However, I think there are really important differences between La Forge and Courtermont. On the one Hand. And Malebranche, on the other hand, La Forge and Cour d' Amoise are primarily philosophers. La Forge was a physician, Cordemois was a lawyer. They weren't theologians. And even though they do speak of the eternal infinite mind, or being who is the cause of motions and various events in the human mind, they are not like Malebranche theologians, seeking to demonstrate our thoroughgoing dependence on God. Malebranche is a Cartesian, but he's also an Augustinian. And his occasionalism is much more theologically motivated, like, in fact, all aspects of his philosophical system, his epistemology, his metaphysics, his theories of grace. There's not a theory of grace in La Forge and Quarterma. There is a very significant theory of grace, an occasionless theory of grace in Malebranche. So I think we're better off thinking of Malebranche as a Cartesian theologian, whereas La Forge, he's a great philosopher. I love ma, but his project is primary, theological. Whereas La Forge and Cornmois, I think, are primary philosophers.
A
Yeah, it's almost like they're backwards, because Cornwall and La Forge postulate God as the cause of everything that's happening, because they just need something to do it. So. Oh, God, that's a good explanation. So they're really thinking of it. Yeah. Faux du. We're doing French philosophy. Why not? So for lack of anything better, they postulate God as the cause, the true cause, that's explaining these things for which physical bodies and human minds are only occasional causes. Whereas for Malevranche, it's more like he's got a theory of God into which occasionalism fits really well. Is that the basic idea? Yeah.
B
Yeah, I think that's nicely put. Yeah.
A
There's something, though, that I find puzzling here. So if we're talking about the thoroughgoing occasionalism you described at the very start, one of the aspects that you mentioned is that minds, human minds, cannot cause bodies to move. So I can't, for example, decide to lift my arm, and my mind can't do that. So my desire to lift my arm is maybe the occasion for God's doing it right. Something I find a little bit unpersuasive here is why can God do it if my mind can't do it? Right? So, okay, God's infinite, fine and omnipotent. So maybe it's just. The answer is just he can do anything because he's omnipotent. But it seems like if there's metaphysical worries about minds causing bodies to move around while God is an immaterial Mind as well. Right.
B
So that's to remain in that old mythology of occasionalism that is the mind body problem. Okay, but it's not a mind body problem. But this is a great way to look more deeply at the motivations for occasionalism. First of all, minds are impotent within themselves. For a thoroughgoing occasionalist like Malebranche, and I think as well for Cordemois and possibly La Forge, the mind does not even have the capacity, the causal capacity, to generate its own mental state. La Forge, I think, is a little more ambiguous about that. But volitions, for example, are a divine shove that works through the mind. So first of all, human minds don't have any causal efficacy, regardless of what you want to say about their effects on bodies. Second, if there's not a heterogeneity problem, if the motivation for occasionalism is not the ontological differences between mind and body, then there's not a problem about how an infinite mind can move bodies, whereas a finite mind cannot. Which brings us to one of Malebranche's other arguments, what I call the no necessary connection argument. He stipulates as the definition of a cause, that A is the cause of B if and only if there is a necessary connection between A and B. And then he says that you will never find any such necessary connection between finite events. So take for example, my volition to raise my arm, my willing to raise my arm, and the arm rising because I am not an omnipotent being. Even if every time I will to raise my arm, my arm rises, it doesn't follow that it necessarily rises, because not being an omnipotent being, it's conceivable that I should raise my arm and my arm not rise. And so, for example, if my arm happens to fall asleep, or someone's holding my arm. In other words, the nature of being a finite being is a premise in the argument here. But now take God. God is an omnipotent being, and by definition, if an omnipotent being will something, that something necessarily obtains. And so therefore only God satisfies that definition of a true cause, namely that between which whose will and the event there is a necessary connection.
A
I see. So it really is omnipotence that's doing all the work. And the reason it's doing the work is that nothing can stop an omnipotent cause, whereas a non omnipotent cause or a finite cause can always be stopped.
B
Yeah. Although putting in terms of can't be stopped makes it sound as if it's even possible there might something, you know, can't be stopped. But it's stoppable in principle. But it's not even stoppable in principle because that's. That's the nature of omnipotence.
A
Yeah. So maybe putting it that whatever the omnipotent cause decides will necessarily happen. That would be a better way of putting it. Okay, so one thing that we might suspect would follow from all this is, is that there's no such thing as human free will. Because it sounds like God's making everything happen. And for sure, it doesn't sound like I can necessitate anything to happen. I mean, I can't cause anything to happen at all, never mind necessitate it to happen. So at a minimum, God needs to be involved in the causal process. Right. That's very clear from everything we've said. And so we might just think, oh, okay, I see where this is going. Malebranche is going to be a thoroughgoing deterministic. He's going to maybe agree with Calvinism. Right, something like that. But of course, he doesn't say that. He insists that humans are free, and he even says that we can use what he calls inner sensation to be aware of our own freedom. So how can this be reconciled with his occasionalism?
B
This is the perennial question. I think Malbron wrestled with this throughout his entire career. And it really is the biggest challenge for an occasionalist, especially an occasionalist who is a French Catholic in the 17th century who wants to preserve human freedom and especially the freedom to sin. Malvranchius first attempt at solving this is to grant that the will itself is not something that we generate. It's a kind of divine shove that is instituted in each mind. I think of it as a fire hose. Your mind is the hose, and the water rushing through it is the will, and that comes from God. We have, however, the power to direct that will here or there towards this object or that object. And we sin when we direct it towards the wrong object. Malebranche toyed with that solution, and then he realized even that solution granted too much causal power to the will that it can move the hose one way or the other. So he eventually hit upon the following solution. It's still a fire hose. And the will is this divine mental striving that runs through the mind and it lands on objects. So right now, if I'm desiring an ice cream cone, my will is directed towards that. What I have is the capacity to suspend that striving. I can't literally move it by Shoving it this way or that way. But I either allow it to focus on the ice cream cone as opposed to allowing it to focus on something more worthy, or I suspend that consent. So the consent is the default mode. I consent to having the will focus on that object, but I can also suspend that consent, in which case the will then starts moving towards other things. And my freedom, and in fact my virtue, is my capacity to continue suspending that consent until the will lands on a true, eternal, satisfying good, that is God itself.
A
So no ice cream cones, Just God,
B
no ice cream cones.
A
Okay, not great news, but it actually sounds very Stoic, that view. So it sounds a lot like the Stoic view that we have these impressions that are presented to us by the world, and then rational beings, but not animals, are capable of withholding assent. And that's where the Stoic tradition would also locate free will.
B
Yeah, unfortunately, Cartesians like Descartes himself were not very good at acknowledging their sources. Well, except in the case of Malboro, she wants to acknowledge both Augustine and Descartes. But, yeah, it does sound very Stoic in that sense.
A
Yeah. And of course, there's a lot of Stoicism in Augustine, so he could have gotten it through the sources that he's actually acknowledging.
B
Right.
A
So something else that I've been thinking about a lot while reading up on occasionalism is that. And this really goes with the way we've been discussing it, it sounds like a straightforwardly philosophical theory. It's motivated originally by philosophical worries and so on, and yet we're seeing that it has this theological dimension in Malebranche. And also it really seems very strikingly to parallel what was one of the biggest political, religious debates of the period, namely the role of divine grace in human action. And again, occasionalism sounds like it would correlate with a view that puts an immense amount of stress on the role of divine grace. So a Calvinist view, or maybe a Jansenist view within the Catholic tradition. And we've just been talking about Jansenism also over the last few episodes. Malebranche was actually very opposed to the Jansenists. Again, it seems like there's a kind of unanticipated lack of fit here. So on the one hand, it looks like he's got a philosophical theory that would lend itself very nicely to a Jansenist position, but on the other hand, he would stoutly resist that parallel. So how would he explain the difference between himself and the Jansenists?
B
I think, in a number of features. First of all, they differ on the Value of pleasure. Malbranche and Arnaud disagree, for example, on whether pleasure is capable of truly rendering a person happy. Arnaud holding a much more austere view. What's interesting to me as a philosopher is that this ties into their different views on the intentionality of mental states. Malbranch wants to say that pleasure as a state of mind is not necessarily connected with any particular object. And if you suspend the object that your pleasure is directed at, pleasure is capable of rendering a person truly happy. Arnaud wants to say that intentionality is accounted for not by some external object, that your mental state, your pleasure, your sensation is directed at, but that mental states have intrinsic intentionality. That is, the pleasure you get from eating an ice cream cone is intrinsically different from the pleasure you get from contemplating God or doing philosophy. So they differ in their views on pleasure, but more importantly, in terms of grace. Malebranche is much more concerned than a Jansenist like Arnaud with preserving some robust, even if it's occasionalist freedom. Arnaud's Jansenism has, I think, not unreasonably, been accused of coming awfully close to Calvinism and views of freedom and predetermination. But I think the real issue on grace between Arnaud and Malebranche has to do with God's modus operandi in distributing grace. Arnaud wants God to be directly and intentionally responsible for every conferral of grace. God, he says, has a particular volition for distributing grace among those who have been chosen. Malebranche wants to see the distribution of grace, and this ties in with his occasionalism that God distributes grace in a kind of occasionalist manner. So just as the motion of one billiard ball impacting another is the occasion for God to move things in accordance with certain laws of physics, so God distributes grace according to occasions. It's just that in this case, the occasion for the reception of grace is not the motion of a billiard ball, but a desire in the soul of Jesus Christ. And so if Jesus wants this person to receive grace, that will be the occasion for God to distribute grace to that person. What really upsets Arnaud about this is the fact that God is now just distributing things according to rules, rather than in a direct and immediate way. And this kind of law, like distribution of grace, deeply offends, well, lots of things. Arnaud is easily offended. He was the most irrational person in the 17th century. But he really can't accept the idea that divine Providence works in general ways as opposed to particular ways.
A
Is that because he thinks that it's basically tantamount to Pelagianism. So if I just follow the rules, then God has to give me grace. Is that the issue?
B
I hadn't thought about it in that way, but that might be it. It's rather that God's the one who's following the rules.
A
Yeah.
B
That God is not looking at the particularities of this or that person, but simply handing out grace according to what Jesus Christ, who is not an infallible knower, happens to desire on this or that occasion. Okay.
A
The role of Christ actually makes things a lot more complicated there. So it's not like God's following the rule of giving grace to anyone who asks for it, for example, which would be the sort of semi Pelagian position.
B
Yes. Yeah. It's not that you earn it, but rather, and for Malbron, Jesus Christ is a human being, and so the desires in his soul will not be infallible desires. Right. And it may be, therefore, that God's grace will fall on somebody who does not make the proper use of it. To Arnaud, who believes strongly in efficacious grace, that's unacceptable. If God grants you grace, you will make the proper use of it. It's necessarily efficacious. Whereas, just like on the occasionless system, according to the laws of nature, rain may fall on your picnic, or it may fall in the middle of the ocean where it's not needed, as opposed to a recently inseminated field. Nature does not always work to the convenience of the human race. It follows general laws, and sometimes those laws have unfortunate consequences. That's the realm of nature. But the same thing applies in the realm of grace. Sometimes grace falls on not properly prepared soil.
A
Okay, Yeah, I can see why you're saying that. Conrad's view does sound very Calvinist. Right. So basically, God decides who gets grace and who doesn't. And if you get grace, it's efficacious.
B
Always.
A
If not, you're going to hell.
B
Yeah.
A
Speaking of the debates between Malbranche and Arnaud, something we haven't covered yet, but we're about to cover in the next episode, is the debate between the two of them over the question of ideas and vision in God. And you wrote a book about this quite a long time ago in which you remarked that Malebranche's position on ideas. There's a quote from you does for epistemology precisely what occasionalism does for physics. So, as I say, we haven't really covered this yet, but maybe you could help us look ahead to that topic by Explaining what you meant by this remark?
B
Sure. Just as occasionalism shows the absolute, exceptionless dependence that all bodies and all human minds have on God for their causal relations, so the vision and God doctrine shows the absolute exceptionless dependence that human minds have on God for their knowledge. Arnaud wants to say that the ideas that function in human knowing and human perception are modes or states of the human mind, almost the view that you would naturally assume that my ideas are here in my mind, whether it's my mathematical ideas, my moral thoughts, my views on metaphysics, or my sense perceptions. They're all states of my mind. They're all mental states. Malbron wants to distinguish between those states of mind that truly are mental states, sensations, imaginations, pleasures and pains, and qualia. He wants to distinguish those from the intellectual concepts that inform our rational thinking. Those intellectual concepts which Arnaud says are equally mental states. Malvern says no. They are ideas in the divine understanding to which we are granted access by God. Again, what really offends our no, once again, is the notion that we have access to God's understanding, this transparency of God's mind to our mind. But that's Malebranche's view. That's the vision and God doctrine. And so we might get along very well as sensing and passionate beings without God, although, given the occasionalism, we really couldn't. But when it comes to knowledge, real intellectual knowledge, we are as epistemically dependent upon God for that as we are for any causal efficacy we might have in the world.
A
Okay, great. Well, that's a good preview of what we'll be looking at next time. That wraps up things for this time, though, so thank you so much, Steven Nadler, for coming on the podcast.
B
It's my pleasure. Thanks for having me.
A
And I'll invite the audience to join me next time for the Malvernche Arnaud debate over ideas here on the history of philosophy without any gaps.
History of Philosophy Without Any Gaps – Episode 490: Steven Nadler on Occasionalism
Date: April 5, 2026
Host: Peter Adamson
Guest: Steven Nadler, Vilas Research Professor and William H. May II Professor of Philosophy at the University of Wisconsin–Madison
This episode explores the philosophical doctrine of occasionalism, focusing especially on its development in early modern philosophy and the central figure of Nicolas Malebranche. Peter Adamson interviews Steven Nadler, a leading scholar on the subject, tracing occasionalism’s history, motivations, connections to theological debates, and the nuances separating thinkers such as Malebranche from his predecessors and rivals. The discussion covers the definition, origins, philosophical (and theological) motivations behind occasionalism, its implications for mind-body interaction, causation, free will, and divine grace, and concludes with a preview of Malebranche’s influential doctrine of “vision in God.”
[00:36 – 02:48]
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This episode demystifies occasionalism, showing how a seemingly abstract metaphysical doctrine resonated through domains as wide as theology, epistemology, and the politics of religion. Steven Nadler’s insights expose the intricate dances between philosophical innovation and theological orthodoxy in 17th-century France, emphasizing Malebranche as not just a successor, but a transformer of Cartesianism. The conversation both clarifies common misperceptions and lays groundwork for further exploration in the next episode.
Next episode: The Malebranche–Arnauld debate over “ideas” and “vision in God.”