Hume’s Skeptical Argument in Outline


     Copyright © 2010 Bruce W. Hauptli


A. The discussion from pp. 78-82 is devoted to answering negatively the question: “what reason do we pronounce it necessary, that everything whose existence has a beginning, shou’d also have a cause?”.   Here is the core argument regarding A in brief:


79-80 “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 prov’d, we must despair of ever being able to prove the former.  Now that later 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, ‘twill 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 is implies no contradiction nor absurdity; and is therefore incapable of being refuted by any reasoning from mere ideas ; without which ‘tis impossible to demonstrate the necessity of a cause.” 


-82 Hume contends that if “the necessity of a cause” can’t be known (or established) by reasoning, then this “idea” must come from experience.  Thus the question turns into “how [is it that] experience gives rise to such a principle?”  But Hume finds that he can deal with this question by addressing the “second question” above p. 78 (that is: “What is the nature of that inference we draw from the cause to the effect, and of the belief we repose in the causal relation?”). 


B. The discussion from pp. 82-155 is devoted to answering negatively the question: “What is the nature of that inference we draw from the cause to the effect, and of the belief we repose in the causal relation?”  Here is the core argument regarding B in brief:


86-87 “There is no object, which implies the existence of any other if we consider these objects in themselves, and never look beyond the ideas which we form of them.  Such an inference wou’d amount to knowledge, and would imply the absolute contradiction and impossibility of conceiving any thing different.  But as all distinct ideas are separable,  ‘tis evident there can be no impossibility of that kind.” 


87 “‘Tis therefore by EXPERIENCE only, that we can infer the existence of one object from another....We remember to have had frequent instances of the existence of one species of objects; and also remember, that the individuals of another species of objects have always attended them, and have existed in a regular order of contiguity and succession with regard to them.  Thus we remember to have seen that species of object we call flame, and to have felt that species of sensation we call heat.  We likewise call to mind their constant conjunction in all past instances.  Without any further ceremony, we call the one cause and the other effect, and infer the existence of one from that of the other.” 


In short, for Hume, constant conjunction is added to contiguity and succession to give us causation




98 “...when any impression becomes present to us it not only transports the mind to such ideas as are related to it, but likewise communicates to them a share of its force and vivacity.” 


-99 “...when the mind is once inliven’d by a present impression, it proceeds to form a more lively idea of the related objects, by a natural transition of the disposition from the one to the other.” 


118 “There is implanted in the human mind a perception of pain and pleasure, as the chief spring and moving principle of all its actions.  But pain and pleasure have two ways of making their appearance in the mind; of which the one has effects very different from the other.  They may either appear in impression to the actual feeling, or only in idea, as at present when I mention them.  ‘Tis evident the influence of these upon our actions is far from being equal.  Impressions always actuate the soul, and that in the highest degree....” 


119 “Did impressions alone influence the will, we should every moment of our lives be subject to the greatest calamities; because, tho’ we foresaw their approach, we should not be provided by nature with any principle of action, which might compel us to avoid them.” 


C. The discussion from pp. 155-172 is devoted to answering negatively the question: “What is our idea of necessity, when we say that two objects are necessarily connected together?”  Here is the core argument regarding C in brief:


155 Hume notes that since all ideas are derived from impressions, we should ask “From which impression does the idea of necessary connection arise?” 


-He notes that all we find when we investigate, however, is contiguity, succession (or precedence), and repetition


163 On the other hand, Hume notes, “...suppose we observe several instances, in which the same objects are always conjoin’d together, we immediately conceive a connexion betwixt them, and begin to draw an inference from one to another.  This multiplicity of resembling instances,  therefore, constitutes the very essence of power or connexion, and is the source, from which the idea of it arises.  In order, then, to understand the idea of power, we must consider that multiplicity....The repetition of perfectly similar instances can never alone give rise to an original idea, different from that is to be found in any particular instance....” 


172 Hume contends that the “doctrine” that “a cause is necessary for every beginning of existence” (that is, every effect must have a cause”) is not founded on either demonstrative or intuitive knowledge


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File revised on 07/10/2010