Hume as only epistemically skeptical of causation

David Hume is widely recognized for his examination of the concept of causation and its significance in human perception. In his Enquiry Concerning Human Understanding, Hume delineates the extent to which the supposition of connected phenomena, namely cause and effect, is the primary basis for knowledge or assumptions about the material world, and famously proposes a critique of the rationale behind causation known as the Problem of Induction. Hume’s apparent attack on the legitimacy of an understanding so central to human experience can initially be understood as a radical skepticism, but a closer look at his discussion of causation throughout the Enquiry yields considerable doubt about whether or not Hume should actually be considered a skeptic about causation. In this paper I summarize Hume’s account of cause and effect, present his argument concerning the Problem of Induction, and assert that an assessment of Hume’s overall discussion of causation and his firm distinction between empirical experience and a priori reasoning leads to the conclusion that Hume is not, in a specific sense which I will define, skeptical about causation.

An understanding of Hume’s account of cause and effect is imperative to both an understanding of his Problem of Induction and a appreciation of his skepticism towards the phenomenon. Hume begins by dividing all human perception into two categories, impressions and ideas. Impressions are essentially the mental products of sensory experience, and ideas, whether simple or complex, are mental entities derived entirely from impressions. Hume then posits three associations which the intellect can create between ideas, namely resemblance, contiguity, and cause and effect. Resemblance between ideas concerns similarities between the sensory impressions that serve as the basis for ideas, contiguity between ideas concerns an acknowledgment of other parts within a part-whole idea, and cause and effect concerns the supposition of a connection between two ideas where one is consistently experienced as preceding the other. Finally, Hume asserts that “all the objects of human reason or inquiry may naturally be divided into two kinds, namely relations of ideas and matters of fact” (542). To Hume, relations of ideas are limited to concepts with distinct analytic definitions, such as “geometry, algebra and arithmetic” (542). All other human inquiry exists in the realm of matters of fact, and Hume suggests that “all reasonings concerning matter of fact seem to be founded on the relation of cause and effect” (542). These distinctions are essential to a discussion of Hume’s skepticism towards causation because they demonstrate causation’s significance in Hume’s epistemology. To Hume, all human knowledge, with the exception of statements concerning the most abstract mathematical concepts, is associated with cause and effect.

Hume’s precise explanation of cause and effect begins with the acknowledgement that a person exposed to this world will “immediately observe a continual succession of objects, … one event following another” (549). Hume asserts that at first, this person “would not, … by any reasoning, be able to reach the idea of cause and effect, since the particular powers by which all natural operations are performed never appear to the senses,” and that the mere succession between events is not by itself sufficient to yield a mental connection between one event and the next (549). It is only the consistent conjunction of similar objects or events that will lead an individual to “immediately infer the existence of one object [or event] from the appearance of the other,” and Hume asserts that this inference is founded in custom or habit, and not in reasoning (551). Unlike propositions concerning mathematical entities, which reason can lead an individual to believe in immediately because of their analytic definitions, propositions concerning cause and effect are only available after the repetitive conjunction of events, which demonstrates the role of habit and not reason. It is in response to the human tendency to believe in a reasoned or necessary connection between two events — and to label these events cause and effect — that Hume poses his Problem of Induction.

Causation as a phenomenon relies on inductive reasoning, which involves using real experiential data to make conclusions about things that have not been experienced. This type of reasoning becomes attractive when a conclusion made about something not yet experienced turns out to be correct. Correct predictions made about an event intuitively lead to the assumption that a certain uniformity exists in the natural world, and this assumption is often referred to as the Principle of the Uniformity of Nature. However, because this principle concerns matters of fact which lack complete analytic definitions, in order to prove such a principle, one would either have to correctly predict every single natural event which ever occurred, or rely on some principle which would allow them to derive such a conclusion. The only available principle which could be used to justify the Principle of the Uniformity of Nature is itself, and therefore, inductive reasoning relies on inductive reasoning, leading to a circular logic which is entirely untenable. Hume’s Problem of Induction demonstrates that the human belief in causation has no rational foundation.

Now that Hume’s attack on the rationale behind causation has been established, I can turn to other examples from his exploration of causation’s popularity and significance in order to approach a conclusion about whether or not Hume’s position towards the matter should be considered skeptical. Since Hume has asserted that all reasonings concerning matters of fact are tied to cause and effect, it is clear he understands causation to at least hold a significant role in human cognition and behavior. In Section V of the *Enquiry, *Hume makes a distinction between fiction and belief, and suggests there is “some sentiment or feeling which is annexed to the latter, not to the former, which depends not on the will, nor can be commanded at pleasure” (552). He concludes this section with the assertion that the belief in causation “is so essential to the subsistence of all human creatures, it is probable that it could not be trusted to the fallacious deductions of our reason which is slow in its operations … [and] extremely liable to error and mistake” (552, 555). Here, without speaking to its ontological reality, Hume appears to acknowledge that a reaction to the idea of causation has empirical importance, and also to demonstrate a sense of disdain towards reason, both of which are important to my conclusion.

Later, in Section VII, Hume reiterates that a consistent conjunction between two events is insufficient to suggest a *necessary connection between the events *(rendering one cause and the other effect), but asserts that “when we say … that one object is connected with another, we mean only that they have acquired a connection in our thought” (563). He continues, finally defining a cause as “an object followed by another and whose appearance always conveys the thought to that other” (563). While Hume admits that “we cannot … attain any more perfect definition which may point out that circumstance in the cause which gives it a connection with its effect,” reiterating his denial of the necessary connection between material events that seems essential to real physical causation, he is willing to admit a certain degree of causation or connection in the realm of ideas and impressions (563). It is apparent that Hume is convinced in his denial of a genuine causation between physical events, but he is hesitant to deny the phenomenon altogether.

In order to reach a verdict about whether or not Hume should be considered skeptical about causation, it is important to better define skepticism in the scope of Hume’s argument. A skeptical position can be ontological, in the sense than an individual doubts that something exists, or epistemological, in the sense than an individual doubts that something can ever be justifiably believed or known. To ascertain Hume’s own understanding of the term, we can choose to look no further than the Enquiry itself. When defining the characteristic principles of “Academic or skeptical philosophy,” Hume includes “doubt and suspense of judgment, … confining to narrow bounds the inquiries of the understanding, and … renouncing all speculations which do not lie within the limits of common life and practice” (548). He speaks of the importance of fighting the “rash arrogance, … lofty pretensions, and … superstitious credulity” of the mind (548). Later, he asserts that “no conclusions can be more agreeable to skepticism than such as make discoveries concerning the weakness and narrow limits of human reason and capacity” (563). In Hume’s comments on belief and reason from Section V, he echoes the same negative sentiment towards human reason. Here, Hume’s emphasis on sensory impressions, or empirical experience, described in detail earlier, becomes more relevant. In a sense quite opposite from Descartes and other rationalist skeptics who followed, Hume seems to exhibit a skepticism of reason itself, and would rather place his faith in sensory experience when reason clearly falls short. Hume acknowledges that reason is insufficient in providing a justified belief in causation, and is intent on denying the possibility of any a priori knowledge of a necessary connection between events, but it is clear that Hume’s skepticism is of the epistemological variety, and he is happy to rely on a sentimental belief in causation despite its fragility in the realm of reason. If, in the context of this paper, being a skeptic about causation means someone who doesn’t believe that there is such a thing as causation, or someone who is ontologically skeptical about causation, I would agree that Hume is not.