In Humes Enquiry, the principle of custom is analyzed. Hume asserts that customs are developed over time by gathering evidence from the senses. Indeed, cause and effect generates a pattern that becomes expected and, in this pattern, custom is established. These continual experiences, over time, allow one to make generalizations, infer data, and predict outcomes. Such “repetition of any particular act or operation produces a propensity to renew the same act or operation” (An Enquiry concerning Human Understanding, p.28), and this establishes an individual’s unique custom. Furthermore, customs permit actions even in the absence of direct guidance “without being impelled by any reasoning” (Enquiry, p.28), and in many instances exclusive of a clear understanding. Thus, habits guide humans to act immediately and specifically.
Hume establishes the view that custom serves individuals in a manner beyond that of reasoning. In Enquiry, Hume asserts that every matter of fact has been tested through the senses and that “reasonings concerning matter of fact seem to be founded on the relation of Cause and Effect” (Enquiry, p.16). Furthermore, as “causes and effects are discoverable, not by reason, but by experience” (Enquiry, p.17), it is the experience which governs custom. Ultimately, neither an exact nor even a thorough experience is required for an individual to act on an impulse. Hume states, “All inferences from experience, therefore, are effects of custom, not of reasoning” (Enquiry, p.28). That is to say, habits allow one to make an inference based on previous outcomes of similar situations.
The principle theme of inductive reasoning emerges, which maintains that similar effects come from similar causes. Hume insists that “knowledge of this relation is not, in any instance, attained by reasonings a priori, but arise entirely from experience” (Enquiry, p.17). Hume illustrates this concept in the example of one person pushing another. He writes, “But no man, having seen only one body move after being impelled by another, could infer, that every other body will move after a like impulse” (Enquiry, p.28). The logic behind custom maintains that, while there is no guarantee, the conclusion drawn based on experience is likely to be correct. Additionally, any action based on custom can be made independent of understanding since “All inferences from experience, therefore, are effects of custom, not of reasoning” (Enquiry, p.28). Thus customs allow assumptions and actions, which are not controlled by the reasoning process.
For the cynics, human reasoning is a sine qua non for matters of fact and Hume obligingly entertains the skeptical doubts about cause and effect. His reaction to the question “What is the foundation of all our reasonings and conclusions concerning that relation [cause and effect]” (Enquiry, p.20) demonstrates that reason has its limitations. In the example of a bread loaf, Hume explains that “If a body of like colour and consistence with that bread, which we have formerly eat, be presented to us, we make no scruple of repeating the experiment, and foresee, with certainty, like nourishment and support” (Enquiry, p.21). The cause, which in this example is an item that resembles a bread loaf, will, from experience, result in a similar effect i.e. sustenance. This cause-effect relationship develops from experience and the matters of fact beyond experience must be based on custom. To further squelch misgivings on the role of experience, Hume asks, “But why should this experience be extended to future times, and to other objects, which for aught we know, may be only in appearance similar; this in the main question on which I would insist” (Enquiry, p.21). Hume considers the alternate view that experience in no way mandates that a cause will generate the same effect in every instance. In his line of reasoning, Hume maintains that the thought process that one undergoes is beyond reasoning or at least the skeptics must otherwise prove him incorrect. He calls on the skeptics to “produce that reasoning” (Enquiry, p.22).
In conclusion, understanding the cause-effect relationship and experience is fundamental in examining the role of custom as the “great guide of human life” (Enquiry, p.29). Hume states, “I have found that such an object has always been attempted with such an effect, and I foresee, that other objects, which are, in appearance, similar, will be attended with similar effects” (Enquiry, p.22). Using this proposition and logical arguments, Hume attempts to sway the skeptical assumptions regarding cause-effect and reasoning. Hume persuades the doubters to consider the proposition that “demonstrative reasoningâ€¦and moral reasoning” (Enquiry, p.22) presents a logical fallacy in that demonstrative reasoning cannot disprove a cause-effect relationship a priori. Additionally, extrapolations made based on experience, which “are effects of custom” (Enquiry, p.28), allow one “to reach the idea of cause and effect”