Aristotle’s Teleology – 29/02/2016

Aristotle famously claimed that “all men by nature desire the know”. To understand something is to know the answer to the question “why?”, and to be able to do so, we have to understand what the puzzle really is.

Why? Why? Why? Why am I a philosopher, and someone else a baker or guitarist or athlete? Why do birds fly and why are mountains high? Aristotle contends that the answer to questions like this is fourfold. Today, I’ll explain Aristotle’s Doctrine of the Four Causes.

Aristotle discusses theories of his predecessors, among whom the presocratic atomists. They reduced the cause of all movement, change or phenomena to the mechanics of atomic elements, processes which were seen as purposeless by nature. These thinkers had a mechanistic worldview.
Aristotle thought that these philosophers were fundamentally confused about something, which led to their inability to offer satisfying explanations of phenomena: they confused four different kinds of causes.
To understand something, Aristotle believed, you have to understand each of the four causes of that thing. These four causes are:

Material Cause: that out of which a thing comes to be and which persists.
Formal Cause: the pattern, structure of form that the matter realises in becoming a determinate thing.
Efficient Cause: the agent or cause responsible for the thing’s coming into being.
Final Cause: that for the sake of which a thing is done.

Aristotle explains this using the example of a statue. The material cause of the statue is the bronze it is made of, the formal cause is the body of Hercules, the efficient cause is the artist making the statue or the art of bronze-casting, and the final cause is to honour Hercules.

The final cause of each thing is intimately related to its formal cause, and these causes play an important explanatory role that Aristotle’s predecessors ignored.

It is easy to identify these four causes of artefacts, but Aristotle believed that they apply to nature as well. This means he replaces the mechanistic worldview of his predecessors with a teleological worldview: everything in nature has a purpose. Telos is the Greek word for purpose.

But this raises difficulties. Aristotle did not believe that the purpose of everything in nature was determined by an external agent or creator, a “divine craftsman”. Instead, he believed that the purpose of nature is immanent: a thing’s purpose is part of it’s nature. In the words of Jonathan Lear in Aristotle: the desire to understand:

“Real purposefulness requires that the end somehow govern the process along the way to its own realization … it is not, strictly speaking, the end specified as such that is operating from the start: it is form that directs the process of its own development from potentiality to actuality…
Of course, the existence of potential form at the beginning of the developmental process is due to the antecedent existence of actual form. … Ultimately, it is actual form which is responsible for the generation of actual form. So in this sense the end was there at the beginning, establishing a process directed toward the end: actual form.”

This brings us to two more distinctions: form v. matter and actuality v. potentiality. These can be explained thus for a certain form F:

Form: that which makes some matter that is potentially F, actually F.
Matter: that which persists and which is for some Fs, potentially F.

So, I have matter and I have form. It is because of my actual form that I have certain potential. I am, for instance, cut out to be a philosopher. That potential to become a philosopher guides my development to become an actual philosopher. What is your potential, your final cause, your telos?

Elisabeth, Princess of Bohemia and Descartes on Mind/Body Dualism – 15/02/2016

Once upon a time, Rene Descartes sat down in his armchair by the fire, closed his eyes and began to discard every belief he had that he could doubt, hoping to retain only those beliefs that could not be doubted – and that he could therefore hold with certainty.

Since we can easily doubt the senses – it is possible that we are just brains in vats, without a body, being manipulated by an evil demon – Descartes had to discard everything he had ever learned by experience. But if our senses give us only illusions, what can we know at all? Descartes concluded that the only thing we cannot doubt is our own existence. Because if we are indeed manipulated and deceived, then there must be someone that is deceived; there must exist a thinking subject. Hence, Descartes concluded: cogito ergo sum – I think, therefore I am.

Since it is possible to doubt the existence of the world, but not the existence of the thinking subject, Descartes concluded that thinking must be the essence of the mind: the mind is a thinking substance.

Initially, Descartes arrived at his mind/body dualism via a fallacy. Because he couldn’t doubt the existence of the mind as a thinking substance, but he could doubt the existence of the body (or any material thing), these things must be distinct, he thought. But he realised that this doesn’t follow. Just because he has knowledge of the mind, but not of the body, doesn’t mean they are distinct. Therefore, Descartes offered another argument: since the essence of material substances is that they are extended, and extended things cannot think, the mind must be unextended, and therefore immaterial. The body is extended, therefore material, therefore the body must be distinct from the mind. Voila: not only mind/body dualism, but also substance dualism (the view that there are two kinds of substances: material and immaterial).

But one woman wasn’t buying any of this. Descartes corresponded with Elisabeth, Princess of Bohemia, over an extended period of time. Elisabeth was well-read in philosophy, and not easily swayed by Descartes. In one of her letters, she asked an important question: how is it possible that the mind interacts with the body (and also vice versa: that the body interacts with the mind), if they are distinct substances?

Descartes admits that his answer to this question is not satisfactory, and his followers have struggled with it ever since. The aim of this lesson is to appreciate the nature and force of this interaction problem, as it is a problem one has to face if one, for instance, wants to accept an idea of a free will, or an idea of an immortal soul.

Free will – 11/01/2016

Do we have free will?

Ali is a free man, or so he thinks. What he doesn’t know, is that the evil professor Klatz has planted a chip in his brain. This chip in Ali’s brain allows professor Klatz to exercise full control over all of Ali’s decisions. Ali is unaware of this. He experiences his own decision making as if he himself takes his decisions. Ali is free to go wherever he wants, do whatever he chooses to do. Nobody, not even the professor, curbs Ali’s freedom of action. It’s just that the professor controls Ali’s brain in such a way that when he is faced with the choice whether to have porridge or toast for breakfast, the professor makes Ali choose porridge rather than toast, regardless of whether Ali would’ve chosen the same thing if he hadn’t been manipulated.

Meanwhile, Babs is imprisoned in a small cell. She is physically constrained in her freedom of action. She can’t go anywhere and she can’t do many of the things she would choose to do, but this doesn’t stop her fantasizing about what she would do if she hadn’t been confined in a prison cell. But all to no avail: she can’t even arrange her own breakfast. This morning, the prison guard asked her: “What would you like for breakfast, Babs? Porridge or toast?” Babs considers both options and chooses porridge. There is no chip in Babs’ brain and no evil professor controls her decisions, the choice is hers. Yet, it has no influence whatsoever on the actions of the guard; he is just teasing her, he has already made her toast.

Who has free will, Ali or Babs?

A: Babs has free will, but Ali hasn’t. The will is free if you can choose between more than one option and nothing but you determines which of the two you choose. The ability to choose makes the will free. The fact that the physical world Babs lives in makes it impossible for her to manifest those choices is irrelevant.

B: Both Babs and Ali have free will. The will is always free, whether you can cause your own decisions has nothing to do with it.

C: Neither Babs nor Ali have free will. Even professor Klatz has no free will. Free will is an illusion.

D: Ali has free will, but Babs hasn’t (or at the very least the freedom of her will is severely limited). Regardless of how a decision is caused, one can only truly speak of freedom of the will if the decision, once it is made, can be acted upon. Babs’ fantasies are not real exercises of a free will.


Philosophers have distinguished freedom of the will from freedom of action for centuries. But do we have a free will? How we answer that question depends on what we understand by freedom of the will. Furthermore, however we answer this question, it will have consequences for how we think about morality, personal identity and a wide range of other philosophical, legal and psychological questions.


A lecture by Daniel Dennett on free will in which he uses this comic strip of Dilbert. He disagrees with Sam Harris, who gives a lecture on his side of the argument. But these are just two of many possible positions on the matter.

This ‘Mind over Masters’ debate between a philosopher, a neuroscientist, a psychologist and a developmental psychologist shows that there are still quite some conceptual misunderstandings between the interlocutors! (is the developmental psychologist talking about the same kind of freedom as the philosopher?) But it also shows that a belief in a free will has real, immediate, implications beyond the realm of philosophy.