Are Hume’s Explanation of Ideas and Impressions Metaphysical?
In seeking for phenomena to prove this proposition, I find only those of two kinds; but in each kind the phenomena are obvious, numerous, and conclusive. I first make myself certain, by a new review, of what I have already asserted, that every simple impression is attended with a corresponding idea, and every simple idea with a correspondent impression. With this constant conjunction of resembling perceptions I immediately conclude, that there is a great connexion betwixt our correspondent impressions and ideas, and that the existence of the one has a considerable influence on the other, Such a constant conjunction, in such an infinite number of instances, can never arise from chance; but clearly proves a dependence of the impressions on the ideas, or of the ideas on the impressions. (Hume 9)
I will be focusing primarily on what Hume says about impressions and ideas in Book 1 Part 1 Section 1 of his A Treatise of Human Nature. Hume begins his Treatise by discussing aspects of knowledge in which he makes clear that he is an empiricist and believes that knowledge comes from experience. He does this though the concepts (and distinctions) between Ideas and Impressions. He argues that when one perceives, specifically in regards to sight and sound, they will experience an Impression. These impressions leave a lasting impact on the individual, and as a result, ideas are formed. These ideas, by my understanding and interpretation, are what each person’s memories and imagination are made up of. Any thought a person has is made up of things (events, objects, sounds; perceptions) that the person has experienced, and are formed either through a representative means or through a means that combines the representations of multiple ideas to form the conception of a single idea. Hume argues that there is a significant connection between ideas and impressions so much so as to believe that they are the basis of all human knowledge.
Hume makes the distinction between complex and simple impressions and ideas. “I venture to affirm, that the rule here holds without any exception, and that every simple idea has a simple impression, which resembles it; and every simple impression, a correspondent idea. That idea of red, which we form in the dark and that impression, which strikes our eyes in the sun-shine, differ only in degree, not in nature.” (Hume 8) Simple impressions and ideas have a direct resemblance in each other, and when the resemblance differs, it is in degree only. Simple impressions therefore are what we use to develop knowledge because they are interpreted easily and when becoming an idea, they remain wholly representative of what they develop from. “I observe that many of our complex ideas never had impressions, that corresponded to them, and many of our complex impressions never are exactly copy’d in ideas. I can imagine to myself such a city as New Jerusalem, whose pavement is gold and walls are rubies, tho’ I never saw any such. I have seen Paris, but I shall affirm I can form such an idea of that city, as will perfectly represent all its streets and houses in their real and just proportions?” (Hume 8) Hume explains ideas in a manner that distinguishes them as differing by more than simply degree, but also by nature from their impressions. One’s idea of an object varies further than the shade or ferocity in which it was first impressed upon them; rather the object, of a complex idea, does not necessarily have a strict representation at all. A complex idea is formed from a number of simple ideas that merge into a more complex unrepresentented object. Just as complex ideas can form from a variety of simple impressions, complex impressions are misrepresented when forming simple ideas. Complex impressions still form ideas; they are just remembered differently than they are perceived. The impression may have too many intricacies, or the agent may be in a state that alters their ability to perceive correctly, which would ultimately alter the ideas that they form. These impressions could form multiple ideas, or simply form incorrect ideas which would explain how different people remember events (they each attended) differently.
The field of metaphysics has made great strides from the time Hume wrote his treatise. With the current emphasis lying in the concept of dispositions, one can make a connection between Hume’s explanation of ideas and impressions, and the field of metaphysics. Between his writing personifying the experience of impressions, and one’s subconscious to draw out ideas from impressions, the conception of Hume’s ideas and impressions has a very physical implication to it. Hume explains impressions as a physical experience, one that would be experienced if an agent held the dispositions necessary to be impressed upon by it.
Understanding Hume’s impressions and ideas as metaphysical will alter how one understands his empirical view, and the necessity for perception in the pursuit of knowledge. Hume explains, throughout the first section of Book 1, that one must perceive in order to learn anything, and if one’s perceptions are cut off, they can clearly not have an understanding of that which they learn through those perceptive traits. This belief relies heavily on the physical aspect of understanding, for if one would lose their sight, and as such their access to visual aspects of learning, they would not be able to properly understand the details of the physical world. This lack of understanding would have a profound effect on how we perceive the world. For if Hume’s ideas and impressions are in fact a metaphysical phenomenon, and other fields of study were to recognize these aspects of understanding, then we could interpret Hume from a less psychological standpoint, and we could make strides towards developing a way for those with perceptual handicaps to gain access to the same knowledge as those without.
Every one of himself will readily perceive the difference betwixt feeling and thinking. The common degrees of these are easily distinguish’d; tho it is not impossible but in particular instances they may be very nearly approach to each other. Thus in sleep, in a fever, in madness, or in any very violent emotions of soul, our ideas may approach to our impressions: As on the other hand, it sometimes happens, our impressions are so faint and so low, that we cannot distinguish them from our ideas. (Hume 7)
Hume argues that the difference between impression and ideas is, generally speaking, easy to distinguish the difference between. However, he does acknowledge that there are exceptions, and goes on to cite examples such as violent emotions. The fact that the difference between ideas and impressions would suggest, to mem at least, that perhaps there isn’t such a clear cut difference between the two. Hume, in recognizing the exceptions, suggests that when one perceives an impression in an altered state, they are unable to process the information clearly. This is the case because the agent’s faculties are not working properly. Like a handicapped person, these impressions get misconstrued and processed incorrectly. If impressions weren’t metaphysical phenomena, they would be more difficult to misinterpret perceptually. For when one is in a rage, their bodily faculties are altered, this alteration affects the way that sense perceptions receive information, and any information that is not processed physically would be less affected by the changes in bodily functions. “Those perceptions, which enter with most force and violence, we name impressions” (Hume 7) It seems that Hume considers perceiving to be a very first hand, very physical experience. His word usage suggests that when an agent experiences an impression, they experience very intensely, they absorb the knowledge enough that it creates a lasting effect and creates an idea.
These ideas, having forced their way into the consciousness of an agent through impressions, effect the agent’s dispositions. The more an agent learns, the more dispositions they will obtain, and the more dispositions an agent obtains, the more they will change who they are, and their interactions to the world, and the way they perceive it. This alteration to perceptions however, does not cause a physical change to the agent’s sense perceptions, which would mean that impressions are still processed in the same manner. However, despite the manner in which the impressions are perceived remaining the same, the ideas formed from the impressions could change insofar as the agent has more information about their perceptions given the ideas they have formed from prior experiences.
I would argue that the very manner in which an agent comes to be impressed upon is, in itself, dispositional. For those with sight are disposed to see when their eyes are open, but those who lack sight, do not share that disposition and therefore cannot experience the same impressions or form the same ideas. Similarly, a deaf person does not share the disposition to hear with a person who can, however, they are more disposed to feel the vibrations caused by sound. In this way, each agent would experience different impressions given their disposition to experience different perceptions.