16 Feb 2009

Hume, A Treatise of Human Nature, Book 1, Part 3, Sect 3 "Why a Cause is Always Necessary" §§184-192

by Corry Shores
[Search Blog Here. Index-tags are found on the bottom of the left column.]

[Central Entry Directory]

[Hume, Entry Directory]
[Hume's Treatise of Human Nature, Entry Directory]

[The following is summary, up to the end where I reproduce this section in full. My commentary is in brackets. Paragraph headings are my own.]

[Directory of other entries in this series.]

David Hume

A Treatise of Human Nature

Book I: Of the Understanding

Part III: Of Knowledge and Probability

Section III: Why a Cause is Always Necessary

§184 Beginning in Question

Previously we sought clues for how the idea of causation's necessary connection is not a priori. We decided to consider related questions. The first question was, why do we deem it necessary that things with beginnings are caused? Philosophy expresses this as a maxim:
whatever begins to exist, must have a cause of existence. (78d)
We usually take this as self-evident, so we never demand it be proven. But Hume will now show that this maxim is not at all self-evident.
if we examine this maxim by the idea of knowledge above-explained, we shall discover in it no mark of any such intuitive certainty; but on the contrary shall find, that it is of a nature quite foreign to that species of conviction. (79a)

§185 There are no Intuitively Certain Relations Implied in the Maxim that 'Things with Beginnings Must have Causes.'

We sometimes are certain about particular notions. This certainty only arises when our comparisons of ideas turn-up unalterable relations held between unchanging ideas. This unvarying relations are:
1) resemblance,
2) proportions in quantity and number,
3) degrees of any quality, and
4) contrariety.
[see §162 for an explanation of this list.] We may be intuitively certain of these relations. And yet, none of them are implied in the proposition: whatever has a beginning has also a cause of existence. This proposition, then, is not grounded on our only means of intuitive certainty. Hence it is not intuitively certain. The only way some might argue otherwise is if they demonstrate that there is another infallible relation, which is implied in the proposition. As soon as someone does so, Hume will take it into consideration.

§186 But We can Conceive Beginnings without Their Causes

Hume will now prove that not only is this proposition not intuitively certain, it is not demonstrably certain either.
If something is necessary, nothing else can be the case. So some want to demonstrate that every new existence has a cause, so to prove their maxim. But in order to do so, they must also demonstrate that nothing can begin to exist without a cause or productive principle.
Hume will show that this second demonstration is impossible. He has us first recall that all distinct ideas are separable from each other [see §47 for more on this principle.] And, the ideas of cause and effect are distinct.
Let's first imagine our match example. If we wished, we can perfectly conceive the idea of the flame. We can also conceive that the flame was non-existent in the previous moment. But we do not thereby also imagining its cause. We just think that in the previous moment the flame did not exist. So we conceive the beginning of the flame's existence, without also conceiving its cause. Thus there is no contradiction or absurdity in separating the concepts of beginning and cause. [And whatever we can conceive is a possibility. See §73 for this principle. Hence no one can say it is impossible for there to be a beginning without a cause.]

§187 No Cause for Hobbes' Theory

Hume now discusses one of Hobbes' theories to show the fallaciousness of other demonstrations that try to prove the above maxim that all beginnings require causes. The basic idea of Hobbes' theory is that there are many possible beginnings, but none are actualized until a cause is presented at the right place and at the right time. And Hume's counter-argument will
1) look at how Hobbes' theory tries to demonstrate that it is absurd to presume that something might begin without a cause. This absurd proposition is supposedly the counter-claim to Hobbes theory. And Hume will also
2) show that the counter-claim is implied in Hobbes theoretical claim. So the absurdity of the counter-claim demonstrates the absurdity of the theoretical claim.

The way Hume will do this is by first pointing out that Hobbes' theory not only says that a cause must be present, but also that it must be present at a specific time and place. Otherwise the un-begun thing will exist eternally as a dormant possibility. We might at first think that it is absurd in this system to presume that something can begin without a cause, but that it is not absurd for something uncaused to have a designated time-space point where it could have begun, had it a cause. But Hume will show that in fact that when we remove the cause's influence, it is also absurd to think that the thing could have begun at some designated time and place had the cause been there.

Let's consider an example to help us grasp Hobbes' theory and Hume's refutation.
We first need to imagine an object that might come to exist somewhere and some time. Let's say Napoleon for example. There are infinitely many points of space in the cosmos. Every one of these points in space endures through an infinity of points in time. Now, Napoleon was born specifically at Corsica on the 15th of August, 1769. If his mother would have died before his birth, then Napoleon would never have been caused to exist. He would then have been eternally suspended, as a possibility, as it were. Also, if he were born at some other time or place, then the course of events shaping his life would be different, and hence it would not be the Napoleon that we know. However, he was in fact born at his appropriate and determinate time and place. So his existence was "fixed" or anchored to that time-space point. This is roughly Hobbes' theory. We see that without its cause acting-on just the right time-space point, the thing would never have been begun. Thus his theory accounts for why a cause is necessary for any beginning.

To explain Hume's rebuttal, let's first see what Hobbes' theory asks us to suppose. First imagine any one space-point. Now consider how it endures through time. At each moment of time for each spatial point, a different entity could begin there, if its proper cause acts on that point. Now imagine not just Napoleon, but also an alternate Napoleon, call him Napoleon Z. This alternate Napoleon Z was supposed to be born one day later, the 16th of August, on the nearby island Sardinia. The only way this would be possible is if Napoleon's mother gave birth a day later in a nearby place. So we know where this alternate Napoleon' time-space coordinates were. But his mother was not giving birth at that place and time. So this alternate Napoleon never began his existence. He remained in "eternal suspense."

Now Hobbes seems to presume that we can think of Napoleon Z's beginning spot without thinking of his cause. However, Hobbes also wants us to think of the real Napoleon's beginning as unthinkable without also thinking his cause. In other words, Hobbes argues we can conceive Napoleon Z's time-place without a cause, but we cannot think the real Napoleon'sbeginning without a cause. The essence of Hume's rebuttal is that Hobbes cannot have it both ways. He cannot presume that that is absurd in the one case to have a beginning without a cause, but not absurd for Napoleon Z to have a determinate beginning-point without also having a cause.

So Hume first asks is it more difficult to suppose
a) that Napoleon began existing without a cause,
than it is to suppose
b) that Napoleon and Napoleon Z both have a designated time-space beginning point, even if their cause does not present itself at that place and moment.

Hume's point is that it is just as difficult to imagine something beginning without a cause as it is to imagine a specific beginning place for something that never begins.

Hume says that this system has us wonder two things:
First, whether the thing will begin: so, will Napoleon Z begin? and
Second, where and when the thing begins: so, where is Napoleon Z's determinate time-space point?

But if we answer no for the first question, and say that Napoleon Z does not begin, why would we ask the second question? So if something does not begin, then it is absurd to think that it has a determinate place and time where it begins. We are supposed to conclude that it is absurd to conceive of Napoleon beginning without something causing his beginning. And that absurdity is supposed to prove that Napoleon preexisted his beginning, and needed a cause to come into existence. But that also implies that Napoleon Z preexisted his beginning. So the absurdity of Napoleon beginning without a cause does not make Napoleon Z's unactualized pre-existence any less absurd. In fact, if it is true that the real Napoleon had to wait for the right conditions to occur at some specific time-place point, then it must be true that Napoleon Z had to wait for eternity. But it is just as absurd to say that the real Napoleon could have existed without a cause as it is to say that Napoleon Z is waiting for a cause at a predetermined time-place point, and that this cause never produces itself.

§188 Clarke's Circular Cause

Hume now addresses Samuel Clarke's argument that beginnings must have causes.
His argument begins by taking into account the things that exist. Clarke says that either
1) they were caused,
or, if nothing else causes them, then
2) they must have caused themselves. For otherwise there is no other way to account for their existence.

So Clark wants to prove that all things have a cause. He will do so by showing that even if you deny that things have causes, you still must presuppose that they are caused.

Hume notes that we began by presuming that the thing does not have a cause. Therefore, there can be no cause for it, neither by something else, nor by itself. For even to be the cause of oneself is still to suppose that the thing is caused. Thus to suppose that there is no cause for a self-caused thing implies that it does not exist. So to infer that the uncaused object is self-caused contradicts the reductio presupposition that the thing was never caused to begin with.

§189 Is Hume's Argument Restrained under Locke?

Hume then addresses Locke's argument for the necessity of causation to all beginnings.
Locke argues that
1) We cannot conceive of how 'Nothing' might equal two right angles. This is because 'nothing' is not something.
2) A cause is something. So,
3) Some thing cannot be caused by nothing.
4) Now, if some thing is produced without a cause, it is caused by nothing. But we just saw that no thing can be caused by nothing. Hence,
3) Everything must have a cause.

§190 Locke Turned in Circles

Hume tackles this argument much like the previous ones. They are based on a reduction to absurdity. They want to prove that all objects have causes. So they first suppose that some object does not have a cause. That means
a) the object itself cannot be a cause of itself, for that is to suppose a cause; and, we just began by supposing there are no causes. Also,
b) 'nothing' itself cannot be considered a cause. For again we are supposing a cause while presupposing there are no causes whatsoever.

So from the beginning these arguments are in contradiction with themselves. Thus any absurd conclusion we draw does not mean that we may also regard as absurd the original reductio supposition, that things do not have causes.

We can see that these arguments are circular. We begin by wanting to prove that all things have causes. Then we deny the claim, supposing that something does not have a cause. Then we make the circular inference that if something does not have a cause, then it is caused by either itself or by nothing. To make this inference implies that we are supposing that all things have causes. But that is the very conclusion this inference is supposed to prove. Hence the arguments are circular.

§191 Frivolous Fallacies

Hume addresses now what he considers to be an even more "frivolous" argument:
1) We have effects. The question is, do they have causes?
2) It is implied in the definition of an effect that it have a cause, "effect being a relative term, of which cause is the correlative." (82a) An effect without a cause is technically not an effect to begin with. Hence
3) All things must have causes.
In other words, whenever we presuppose that effects do not have causes, we obtain a contradiction. Then we jump to the conclusion that all things must have causes.
Hume refutes this argument by first pointing out an absurd parallel argument:
a) every husband must have a wife, for it is in the definition of husbands to have wives. Otherwise he would be a widower or bachelor. Hence,
b) every man must have a wife.

To expose the specific fallacy, let's simplify the form for both of them:
I) every husband is a man [all husbands are men],
II) every husband has a wife [all husbands are men-who-have-wives], therefore
III) every man has a wife [all men are men-who-have-wives].
i) every effect is a thing [all effects are things]
ii) every effect has a cause, [all effects are caused-entities] thus
iii) every thing has a cause [all things are caused-entities.]
When formalized we have
x) all A are B
y) all A are C, therefore
z) all B are C.
Here the middle term, A (effects, husbands) does not refer to every member in B (things, men) even though it does refer to every member of C (caused-entities, men-who-have-wives) For, some things might not be effects, and some men might not be husbands. This the middle term is not completely distributed in the premises.
Consider instead if it were properly distributed:
1) All domesticated canids are dogs
2) All domesticated canids are canine animals, thus
3) All dogs are canine animals.
This argument works, because every dog is a domesticated canid, and every canine animal is a domesticated canid. Hence we may remove the middle term, and conclude that all dogs are canine animals.
Thus we know that someone commits the fallacy of undistributed middle when they argue that 'all things must have causes' by using the reasoning that
a) all effects have causes, and
b) all effects are things.
For, the term "effects" does not apply in all cases of things. If we were to presume that all things are effects, that is the same as presuming that all things have causes. For, to be an effect means to have a cause. However, for a reductio, we are presupposing that not all things have causes. So we cannot say that all things are effects. Hence we cannot conclude that all things have causes.

On account of all Hume's above arguments, we see that it is neither intuitively certain nor demonstrably certain that all objects that begin to exist must on that account have some cause.

§192 Experience is Necessarily the Cause for Causal Necessity

Here then is Hume's grand conclusion:
1) We know from the above arguments that our belief in the necessary connection between cause and effect is not obtained either from knowledge or from scientific reasoning. In other words, we have no a priori grounds for our belief that there is a necessary connection between causes and effects.
2) The only other possibility is that we obtain this belief from observation and experience. So in other words, the belief in this connection's necessity is grounded in a posteriori knowledge.

Hume's next question is: how does experience give rise to this principle of the necessary causal connection? For convenience, Hume rephrases the question to:
a) why do some causes necessarily have certain effects? and
b) why to we infer the effects from these particular causes?

We will now pursue these two questions, and find that the same answer applies to both.

From the original text:

Sect. iii. Why A Cause is Always Necessary.

To begin with the first question concerning the necessity of a cause: It is a general maxim in philosophy, that whatever begins to exist, must have a cause of existence. This is commonly taken for granted in all reasonings, without any proof given or demanded. It is supposed to be founded on intuition, and to be one of those maxims, which though they may be denyed with the lips, it is impossible for men in their hearts really to doubt of. But if we examine this maxim by the idea of knowledge above-explained, we shall discover in it no mark of any such intuitive certainty; but on the contrary shall find, that it is of a nature quite foreign to that species of conviction.

All certainty arises from the comparison of ideas, and from the discovery of such relations as are unalterable, so long as the ideas continue the same. These relations are RESEMBLANCE, PROPORTIONS IN QUANTITY AND NUMBER, DEGREES OF ANY QUALITY, and CONTRARIETY; none of which are implyed in this proposition, Whatever has a beginning has also a cause of existence. That proposition therefore is not intuitively certain. At least any one, who would assert it to be intuitively certain, must deny these to be the only infallible relations, and must find some other relation of that kind to be implyed in it; which it will then be time enough to examine.

But here is an argument, which proves at once, that the foregoing proposition is neither intuitively nor demonstrably certain. We can never demonstrate the necessity of a cause to every new existence, or new modification of existence, without shewing at the same time the impossibility there is, that any thing can ever begin to exist without some productive principle; and where the latter proposition cannot be proved, we must despair of ever being able to prove the former. Now that the latter proposition is utterly incapable of a demonstrative proof, we may satisfy ourselves by considering that as all distinct ideas are separable from each other, and as the ideas of cause and effect are evidently distinct, it will be easy for us to conceive any object to be non-existent this moment, and existent the next, without conjoining to it the distinct idea of a cause or productive principle. The separation, therefore, of the idea of a cause from that of a beginning of existence, is plainly possible for the imagination; and consequently the actual separation of these objects is so far possible, that it implies no contradiction nor absurdity; and is therefore incapable of being refuted by any reasoning from mere ideas; without which it is impossible to demonstrate the necessity of a cause.

Accordingly we shall find upon examination, that every demonstration, which has been produced for the necessity of a cause, is fallacious and sophistical. All the points of time and place, say some philosophers [Mr. Hobbes.], in which we can suppose any object to be-in to exist, are in themselves equal; and unless there be some cause, which is peculiar to one time and to one place, and which by that means determines and fixes the existence, it must remain in eternal suspence; and the object can never begin to be, for want of something to fix its beginning. But I ask; Is there any more difficulty in supposing the time and place to be fixed without a cause, than to suppose the existence to be determined in that manner? The first question that occurs on this subject is always, whether the object shall exist or not: The next, when and where it shall begin to exist. If the removal of a cause be intuitively absurd in the one case, it must be so in the other: And if that absurdity be not clear without a proof in the one case, it will equally require one in the other. The absurdity, then, of the one supposition can never be a proof of that of the other; since they are both upon the same footing, and must stand or fall by the same reasoning.

The second argument[Dr, Clarke and others.], which I find used on this head, labours under an equal difficulty. Every thing, it is said, must have a cause; for if any thing wanted a cause, it would produce ITSELF; that is, exist before it existed; which is impossible. But this reasoning is plainly unconclusive; because it supposes, that in our denial of a cause we still grant what we expressly deny, viz. that there must be a cause; which therefore is taken to be the object itself; and that, no doubt, is an evident contradiction. But to say that any thing is produced, of to express myself more properly, comes into existence, without a cause, is not to affirm, that it is itself its own cause; but on the contrary in excluding all external causes, excludes a fortiori the thing itself, which is created. An object, that exists absolutely without any cause, certainly is not its own cause; and when you assert, that the one follows from the other, you suppose the very point in questions and take it for granted, that it is utterly impossible any thing can ever begin to exist without a cause, but that, upon the exclusion of one productive principle, we must still have recourse to another.

It is exactly the same case with the third argument[Mr. Locke.], which has been employed to demonstrate the necessity of a cause. Whatever is produced without any cause, is produced by nothing; or in other words, has nothing for its cause. But nothing can never be a cause, no more than it can be something, or equal to two right angles. By the same intuition, that we perceive nothing not to be equal to two right angles, or not to be something, we perceive, that it can never be a cause; and consequently must perceive, that every object has a real cause of its existence.

I believe it will not be necessary to employ many words in shewing the weakness of this argument, after what I have said of the foregoing. They are all of them founded on the same fallacy, and are derived from the same turn of thought. It is sufficient only to observe, that when we exclude all causes we really do exclude them, and neither suppose nothing nor the object itself to be the causes of the existence; and consequently can draw no argument from the absurdity of these suppositions to prove the absurdity of that exclusion. If every thing must have a cause, it follows, that upon the exclusion of other causes we must accept of the object itself or of nothing as causes. But it is the very point in question, whether every thing must have a cause or not; and therefore, according to all just reasoning, it ought never to be taken for granted.

They are still more frivolous, who say, that every effect must have a, cause, because it is implyed in the very idea of effect. Every effect necessarily pre-supposes a cause; effect being a relative term, of which cause is the correlative. But this does not prove, that every being must be preceded by a cause; no more than it follows, because every husband must have a wife, that therefore every man must be marryed. The true state of the question is, whether every object, which begins to exist, must owe its existence to a cause: and this I assert neither to be intuitively nor demonstratively certain, and hope to have proved it sufficiently by the foregoing arguments.

Since it is not from knowledge or any scientific reasoning, that we derive the opinion of the necessity of a cause to every new production, that opinion must necessarily arise from observation and experience. The next question, then, should naturally be, how experience gives rise to such a principle? But as I find it will be more convenient to sink this question in the following, Why we conclude, that such particular causes must necessarily have such particular erects, and why we form an inference from one to another? we shall make that the subject of our future enquiry. It will, perhaps, be found in the end, that the same answer will serve for both questions.


Hume, David. A Treatise of Human Nature. Ed. L.A Selby-Bigge. Oxford: Clarendon Press, 1979.

Text available online at:


PDF available at:

No comments:

Post a Comment