In this essay I will be concentrating on David Hume’s (1711-1776) views on cause and effect and whether or not he concluded that causes have the power to bring about effects in this world. First off I will be defining what a cause and effect are, and also giving the definition of cause that Hume himself gave. That will be followed by defining Hume’s fork, and his argument that cause and effect are linked by experience, and then followed by his arguments for why this is not a reasonable thing to do, comparing two propositions that represent the link between cause and effect within the human mind and how they do not actually follow each other. Followed by further examples of the problems of linking cause and effect, and finally what Hume was attempting to do by pointing out such gaps in our thinking, ending with his conclusion and my own about what Hume in fact thought about the link between them in this world. (All italics contained in all quotations within this essay are David Hume’s).
First of all, the terms cause and effect are used to signal the action and the effects which form from said action. For example the cause of pulling a trigger will result in the effect of a bullet being propelled. Or for a simpler example: Pushing my hand against a light object with a force stronger than the weight of said object, will produce the effect of moving that object via the cause of my hand and its weight.
Hume used his own definitions of causes within his work, such as:
“We may define a cause to be an object, followed by another, and where all the objects similar to the first are followed by objects similar to the second. Or in other words where, if the first object had not been, the second never had existed. The appearance of a cause always conveys the mind, by a customary transition, to the idea of the effect. Of this also we have experience. We may, therefore, suitably to this experience, form another definition of cause, and call it, an object followed by another, and whose appearance always conveys the thought to that other.” (1)
As well as this Hume also divided human reason into two terms. Commonly referred to as Hume’s fork:
- Relations of ideas:
Such as mathematics – To say that 1+1=4 is a contradiction.
- Matters of fact:
Such as “The sun will/will not rise tomorrow. – To say either is not a contradiction, but a matter of experience.
With Hume, he argued that a cause and effect could not be logically linked together, or at least proved to be. A cause can not, under our current understanding, be proven to actually cause the effect. They merely happen separately and are linked by ourselves as being intimately related, when that may not be the case. So to argue that effects are different events from their causes, means that there is no contradiction in saying that a cause can happen without its usual effect occurring. Hume believes that causal judgements are so familiar and usual to us that we often, if not always, overlook this because such conclusions are so intuitive to our thinking and experience of reality. He made this clear by using an argument about a question concerning the link between cause and effect:
“Shou’d it be said, that we have experience, that the same power continues united with the same object, and that like objects are endow’d with like powers. I would renew my question, why from this experience we form any conclusion beyond those past instances, of which we have experiences. If you answer the question in the same manner as the preceding, your answer gives still occasion to a new question of the same kind, even in infinitum; which clearly proves, that the foregoing reasoning had no just foundation.” (2)
Now at first this sounds counter intuitive, but what he means is: our experience of an effect which is caused by a cause is exactly that: An experience. It is an a posteriori form of knowledge, it is gained by experience and observation, and not by definition or reasoning.
Hume sums this view up in his Enquires:
“Even after one instance or experiment, where we have observed a particular event to follow upon another, we are not entitled to form a general rule, or foretell what will happen in like cases; it being justly esteemed an unpardonable temerity to judge of the whole course of nature from one single experiment, however accurate or certain. But when one particular species of event has always, in all instances, been conjoined with another, we make no longer any scruple of foretelling one upon the appearance of the other, and of employing that reasoning, which can alone assure us of any mater of fact or existence. We then call the one object, Cause; and the other, Effect. We suppose that there is some connexion between them; some power in the one, by which it infallibly produces the other, and operates with the greatest certainty and strongest necessity.” (3)
Because of this you can not conclude that because I eat this dinner that I will gain energy. Because I am basing it on past experience and thus I am assuming and not logically concluding. To say that because yesterday or earlier that my dinner filled me and produced energy says nothing about the future of doing such an action.
This problem can be made clearer by putting forward two different propositions:
- I’ve found that being filled and gaining energy is always followed by eating food.
- Eating foods similar to the ones I’ve eaten in the past will fill me and give me energy.
Using these two propositions we commonly: “Without any further ceremony, we call the one cause and the other effect, and infer the existence of the one from that of the other.” (4)
Now as can be seen by these two statements, if you were to conclude both it would be a circular argument. You can from experience, logically conclude the first, but to conclude them both together: while it may be reasonable, is not factual and may not be the future which is about to take place via the effects. Purely because the second proposition is an assumption based from past experience. To conclude that the future will be like the past does not seem to be as logical as first stated and assumed to be.
For example if every time I take food, my hunger goes. I can only assume that taking food of that kind in the future will cause the effect of taking away my hunger. Seeming as their doesn’t need to be uniformity in effects to their causes according to our expectation, it does not logically conclude that the effect would be like, or linked to the cause. In this way it is reasonable to conclude that the cause may happen without the effect ever following it, or the effect that following it not conforming to the expectation. With this in mind, it is illogical to assume the effect of said cause as we only know by experiencing the effect itself, which hasn’t happened yet. And when it does, it only tells you about that exact cause and what resulted as an effect in what just happened, which only tells you about that case only. Thus, cause and effect are placed in the category of Matters of fact.
To put it simply: Just because my meal fills me today and this time, doesn’t mean it will next time. The problem with this is it destroys our common sense. He is correct to say it is illogical to conclude via experience that we will always gain the same experience via the same cause. However, while identifying similarities among things (As in my example: food) will help you to make a reasonable assumption, but not know the future: You will know the cause but the effect will never be certain, only reasonably guessed at. Only habit and repeated results cause our idea of the intimate link between cause and effect in Hume’s opinion.
Hume sets down in his Treatise of human nature what would be necessary to fix cause and effect together:
“When we infer effects from causes, we must establish the existence of these causes; which we have only two ways of doing, either by an immediate perception of our memory or senses, or by an inference from other causes; which causes again we must ascertain in the same manner, either by a present impression, or by an inference from their causes, and so on, till we arrive at some object, which we see or remember. ‘Tis impossible for us to carry on inferences in infinitum; and the only thing, that can stop them, is an impression of the memory or senses, beyond which there is no room for doubt of enquiry.” (5)
With this Hume concludes that cause and effect is only known a posteriori, and that the source of the idea, which we conclude as the necessary connection between the cause and effect is actually within us, and not in the objects themselves, or even in the ideas of those objects which we label cause and effect. The idea of cause and effect is assumed via our experience and custom in this world, the idea that they are linked is within us and an assumption.
To conclude: it seems that Hume did not think that there are causes in this world that have the power to bring about their effects, and we have made a fundamental mistake by thinking of things in those terms. While reason can justify the connection between cause and effect, it cannot explain it. And this is Hume’s fundamental point in his argument: that although it could be so that the cause is connected to the effect: that the effect was and is directly caused by the cause, and the effect is the result; we, via our reason and logic, cannot show it to be objectively so. We must assume via experience and make an a posteriori conclusion it is so. Hume was, after all, laying the sceptical foundations for the next generations to try and resolve such an issue, as he makes clear in his statement in the Enquires:
“If experience and observation and analogy be, indeed, the only guides which we can reasonably follow in inferences of this nature; both the effect and cause must bear a similarity and resemblance to other effects and causes, which we know, and which we have found, in many instance, to be conjoined with each other. I leave it to your own reflection to pursue the consequences of this principle.” (6)
1. David Hume, Enquiries concerning Human Understanding and concerning the Principles of Morals: An enquiry concerning human understanding; Section VII. Of the idea of necessary connexion, paragraph 60, pp.76-77. (Oxford university press, third edition, 1985.)
2. David Hume, A treatise of human nature and dialogues concerning natural religion, Vol.I., Part III. Of knowledge and probability. Sect.VI. – Of the inference from the impression to the idea, p.392. (London: Printed by Spottiswoode and Co., New street square and parliament street ((No date specified))
3. David Hume, Enquiries concerning Human Understanding and concerning the Principles of Morals: An enquiry concerning human understanding; Section VII. Of the idea of necessary connexion, paragraph 59, pp.74-75. (Oxford university press, third edition, 1985.)
4. David Hume, A treatise of human nature and dialogues concerning natural religion, Vol.I., Part III. Of knowledge and probability. Sect.VI. – Of the inference from the impression to the idea, p.388. (London: Printed by Spottiswoode and Co., New street square and parliament street ((No date specified))
5. David Hume, A treatise of human nature and dialogues concerning natural religion, Vol.I., Part III. Of knowledge and probability. Sect.IV. – Of the component parts of our reasoning concerning cause and effect, p.384. (London: Printed by Spottiswoode and Co., New street square and parliament street ((No date specified))
6. David Hume, Enquiries concerning Human Understanding and concerning the Principles of Morals: An enquiry concerning human understanding; Section XI. Of a particular providence and of a future state, paragraph 115, p.148. (Oxford university press, third edition, 1985.)
– David Hume: A treatise of human nature and dialogues concerning natural religion, Vol.I. (London: Printed by Spottiswoode and Co., New street square and parliament street. ((No date specified))
– David Hume: Enquiries concerning Human Understanding and concerning the Principles of Morals (Oxford university press, third edition, 1985.)