Hume's An Enquiry Concerning Human Understanding

Hume’s An Enquriy Concerning Human Understanding

David Hume’s An Enquiry Concerning Human Understanding (1748) is an investigation of how knowledge is acquired by human understanding, and is an examination of what defines the limits of what can be known. The Enquiry develops themes which were presented in Hume's earlier work, A Treatise of Human Nature (1739).

The Enquiry is divided into twelve sections, entitled: “I: Of the Different Species of Philosophy;” “II: Of the Origin of Ideas;” “III: Of the Association of Ideas;” “IV: Sceptical Doubts concerning the Operations of the Understanding;” “V: Sceptical Solution of these Doubts;” “VI: Of Probability;” “VII: Of the Idea of Necessary Connection;” “VIII: Of Liberty and Necessity;” “IX: Of the Reason of Animals;” “X: Of Miracles;” “XI: Of a Particular Providence and of a Future State;” “XII: Of the Academical or Sceptical Philosophy.”

Hume begins by noting that a memory of a perception is almost never as clear as the original perception. He argues that perceptions may be of two kinds: 1) “thoughts” (or ideas), and 2) “impressions” (or sensations).

Hume claims that all ideas are originally derived from sensory experience. He argues that when we analyze empirical propositions, we need to determine which sensory experience each idea is derived from.

According to Hume, every idea corresponds to a sensory experience. There are no ideas which are innate in the human mind. Every idea is originally derived from a sensory perception.

Hume claims that there may be three kinds of association or connection between ideas: 1) resemblance, 2) contiguity in time or place, and 3) cause or effect. He admits that contrast or contrariety may be another connection among ideas, but explains that contrariety may be considered to be a mixture of resemblance and causation, because when two objects are contrary to each other, they may contradict each other or may cause each other's annihilation.

According to Hume, relations with which reason and experience are concerned may be divided into two kinds: 1) relations of ideas, and 2) matters of fact. Mathematical equations are examples of relations of ideas. Relations of ideas may be discoverable by reason alone, and may not depend on sensory experience for their demonstration. Matters of fact, on the other hand, may not be discoverable by reason alone, and may depend on sensory experience for their demonstration.

Reasoning concerning matters of fact may be founded on the relation of cause-and-effect. By considering this relation between empirical objects, reason may be able to demonstrate matters of fact which are not discoverable by direct sensory experience. Reason may apply the relation of cause-and-effect to various phenomena in order to make inferences about matters of fact that are beyond direct experience.

According to Hume, the relation of cause-and-effect as applied to objects or events is the most important relation which may be established by our reasoning about matters of fact. The idea of causation may arise from our ideas about: 1) the contiguity of various objects or events, 2) the temporal precedence of one object or event before another, 3) the constant conjunction of various objects or events, or 4) the necessary connection of various objects or events.

The temporal or spatial contiguity of various objects or events may give rise to the idea that they may have a cause-and-effect relation to each other. The temporal precedence of one event before another may also give rise to the idea that they may have a cause-and-effect relation to each other. The constant conjunction of various objects or events may also give rise to the idea that they may have a cause-and-effect relation to each other. Finally, the necessary connection which may seem to occur between various objects or events may give rise to the idea that they have a cause-and-effect relation to each other.

Hume explains that our reasoning concerning cause-and-effect relations arises from experience when we find that various objects or events are temporally or spatially contiguous, regular in succession, and constantly conjoined. However, he insists that the idea of necessary connection cannot be confirmed by sensory experience.

Hume also explains that causes and effects may be discoverable by experience, but that they may not be discoverable by reason alone. Every effect is distinct from its cause, and every cause is distinct from its effect. Therefore, an effect cannot be discovered in a causal object or event merely by a priori reasoning. A relation of cause-and-effect between various objects or events must be demonstrated by reasoning from analogy, experience, and observation.

Beliefs may be ideas which are considered to be true in the absence of definitive knowledge or proof. Beliefs may be reasons for our actions. Beliefs may arise concerning the relations of ideas, or concerning relations of cause-and-effect.

According to Hume, there are two kinds of reasoning: 1) demonstrative, and 2) moral. Demonstrative reasoning concerns relations of ideas. Moral reasoning concerns matters of fact (or of existence).

Hume explains that all arguments concerning relations of existence are based on reasoning about relations of cause-and-effect. Any arguments concerning the nature of cause-and-effect relations must ultimately be proven or disproven by experience. Any experimental conclusions which we may draw about the existence of cause-and-effect relations must be based on the assumption that the future will conform to the past.

Arguments from experience may also be based on demonstrating a relation of similarity between objects or events. From similar causes, we may expect to find similar effects.

For Hume, each transition of thought which we make from defining a cause to defining an effect must be based on experience. We cannot prove the existence of cause-and-effect relations solely by the use of reason. We cannot prove that any event is necessarily caused by any other event. We cannot prove that there is any necessary connection between a cause and an effect, and can only demonstrate that a cause and an effect may be temporally or spatially contiguous, regular in succession, and constantly conjoined.

According to Hume, the mind’s command over itself is limited, as is its command over the body. These limits are not known by reason, but only by experience and observation.

Hume explains that, just as we cannot prove that there is any necessary connection between events in the external world, we cannot prove that there is any necessary connection between internal events in the mind. The question of liberty or of necessity has the same significance for events in the external world as it has for internal events in the mind.

Hume argues that liberty, as expressed by voluntary action, may be a power of acting or not acting according to the determinations of the will. Thus, liberty is not contradictory to moral necessity, but is contradictory to moral constraint. Moreover, the power to act or not to act according to the determinations of the will is not contradictory to the finding that there is no necessary connection between a voluntary action and a determination of the will.

If, on the other hand, liberty is defined as the power of the will to cause voluntary action, then a relation of cause-and-effect may have been assumed to exist between the will and voluntary action. However, we cannot demonstrate by experience that there is any necessary connection between voluntary action and the determinations of the will. The power of the will to cause voluntary action may not be capable of being demonstrated if it is simply the reverse of necessity. Thus, we may not be able to prove the existence of liberty, any more than we may be able to prove the existence of necessity.

According to Hume, we may often assume that everything that exists has a cause for its existence. However, when we explore the nature of causation, we find that we cannot prove that a cause is necessarily that by which something exists. We may only be able to show that a cause is that after which something exists. We have no means by which we can prove that a necessary connection may occur between a cause and an effect. Any inferences which we may draw from a cause to an effect, or from an effect to a cause, may have to be based on our experience of a constant conjunction of the cause and the effect, or of a regular succession of the cause and the effect, or of the contiguity in time or place of the cause and the effect.

We may assume that there is an external world whose existence does not depend on our perceptions of it. We may try to show that this external world exists independently of our perceptions of it. However, Hume explains that there is no logical necessity for this conclusion. Based on our own sensory experience, we cannot prove that there is any necessary connection between our perceptions of the world and the world as it really exists. We have only our sensory perceptions as evidence of whether the external world really exists, and thus we cannot reach any conclusions about a necessary connection between our perceptions and objects in the external world.

Thus, Hume argues that knowledge is possible of relations of ideas, but that any truths concerning matters of fact (or of existence) are incapable of being proved to be logically necessary. He emphasizes that all knowledge of matters of fact must ultimately be based on experience, and that such knowledge cannot be based solely on reasoning about relations of logical necessity.

Moral reasoning about matters of fact may be based on previous experience of how they are related to each other, but cannot prove that any relation of cause-and-effect between matters of fact is logically necessary. Thus, any theological or metaphysical arguments which we may make about the nature of ultimate reality may be given their best and most solid foundation by being presented as matters of faith rather than of reason.

Hume’s Enquiry is a brilliant and powerful investigation of the nature of necessity. The implications of Hume’s arguments are very significant for epistemological inquiry. Hume rejects the idea that we can establish any necessary connection between empirical objects or between our perceptions and the external world. Thus, we cannot prove that there is any necessary connection between the appearances of objects and the reality of objects as they are in themselves.

One of the implications of Hume's Enquiry is that many aspects of human understanding may not be governed by the principle of necessity. Human understanding may be contingent to varying conditions, and may not be logically necessary. Human understanding may be limited by a lack of necessary connection between its perceptions and true reality. Thus, Hume’s investigation of the nature and limits of human understanding reveals a profound moral doubt and scepticism.

Copyright© 2001 AlexScott

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