In this exegesis I will attempt to identify and describe Hume’s “Model of the Mind” in Section 2 of Enquiry Concerning Human Understanding: The Origin of Ideas.

In Section 2, Hume begins by explaining the disparity between sensory perceptions and our memories of them. Humans remember things differently to how things actually are and were. He classifies this distinction into two categories: thoughts and impressions by differentiating between the degrees of impact and vividness. Thoughts are less vivid for they are merely conjurings or representations in the mind of what the senses experience. Impressions, he explains, are “more lively perceptions” for they are the sensations of experiences through our five senses. The perceptions of the mind are far less vivid than the impressions. In his own words, “…the most lively thought is still dimmer than the dullest sensation” [sic], Hume here, is distinguishing between the concrete and abstract. Our experiences through our sensory perceptions are concrete and our thoughts and ideas, which are necessitated by these, are abstract. These are the groundwork of Hume’s “model of the mind”.

Hume then delves into the “creative power” of the mindand tells us that our thoughts and ideas rely on associations or mental referents and how we order and make sense of them all. He states, “…this creative power of the mind amounts to no more than the faculty of compounding, transposing, augmenting, or diminishing the materials afforded us by the senses and experience” (Millican, 2007, p. 13). In other words, the creative power of the mind is the human ability to make sense of and process referents—objects and things known and unknown to us in the world—through our sensory perceptions or our “outward and inward sentiments”. Our thoughts are formed and make sense through the impact of the outside world, processed through our senses. The sensations made by the impact affects us emotionally and grants us thoughts of the things which made the impact. Hume’s description of this process can be described as drawing associations. For example, when we say “flying spaghetti monster” (which does not exist), our minds are able to combine and make associations with what we know do exist—the act of flying, the food spaghetti, and something interstitial or known yet unknown—all put together to create the thought and idea of a “flying spaghetti monster”. This is the crux of Hume’s “creative power” of the mind.

With regards to philosophical terms, Hume suggests that these are frequently arrived at without having “any meaning or idea” and much deliberation and inquiry are necessary in determining their validity. Upon encountering certain philosophical terms, one may be quite skeptical about its validity or truth and Hume, once again, suggests that if this philosophical term is not derived from or arrived at through impressions that inform our senses, then whichever is lacking in this process “will serve to confirm our suspicions” about said philosophical term. Answering the question of how one ought to determine the meaning of a philosophical term according to Hume, “we need but enquire, from what impression is that supposed idea derived?” This is necessary if and when a philosophical term escapes what Hume describes as the three principles of association.

In section 3, we are introduced to these three principles: “Resemblance, Contiguity in time or place, and Cause or Effect” (p. 16). These three are anchored to each other in a sequence that is ubiquitous—no general or philosophical ideas or postulations can derive outside of these principles—and necessary for processing the outside world. Hume gives for example, the idea of an apartment in a building, which would then naturally compel one to think of other apartments in the building. In another example, Hume refers to a wound and the mental referent of pain that comes to mind through the association. A billiard ball is struck and smashes into another, causing the smashed to move naturally compels us to associate the movement of billiard ball one with the movement of billiard ball two. Hume suggests that it is merely through repetitive experiences—seeing phenomena unfold before us continuously and having the same results over and over—are these three principles of resemblance, contiguity and cause and effect constants in how we form associations in our human existence.

In Section 4 of Hume’s Enquiry Concerning Human Understanding: Special Doubts About The Operations Of Understanding, he posits that connections or associations are necessary to determine cause and effect. He categorizes these associations as “relations of ideas and matters of fact”—that we do not really know nor understand the relationship between cause and effect—we associate one thing to the other to determine effect. To Hume, events such as the sun rising or the ocean-tide rolling in are all agreed upon events which are established through repetition and experiences. He goes on to suggest that not even through reason can such a relationship be essentially established—only through experiences are we able to discern cause and effect—the mind is incapable of predicting the behavior of things which beget other things solely based on their properties. Even those said properties are unknowable a priori but are only knowable through experiencing the behavior of whatever thing is being experienced. This is the only way we can infer causal connections in nature and outside of Hume’s processes we are not rationally justified in doing so. Furthermore, as it pertains to induction, Hume claims that formal knowledge does not need a necessary connection and requiring one is not justified. He suggests that we do not observe a connection, rather only the spatial temporal contiguity; in other words, we merely make inferences based on what we observe and what is being observed may not be accurate. For example, our perception of the electromagnetic spectrum is limited to our human physical capabilities which fundamentally limits the precision of how the world may be rendered. A simple example would be the way a cat views the world in contrast to a dog and in turn the dog to a human or an eagle. So, for induction, simply saying, “A must cause B” is insufficient for Hume, because it relies on the constant and repeatedly observed contiguous relationship between “A and B”.

If we are to subscribe to Hume’s position on causal connections and induction, we are left to agree that what we experience as humans and determine to be “one thing causing the next” are merely chains of events predictable through past and repeated experiences. This would suggest that our knowledge of anything in the material world is attained solely through our experiences. With scientific knowledge within our cross-hairs, one has to contend with the position that science “does not really know anything” and arriving at a consensus on any knowledge-claim is superfluous and stands on shaky ground. This however, does not render science useless, but is a testimony to science—science is self-correcting—that science relies on harder, stronger data and evidence to overturn widely held beliefs and understandings of life and the world. Perhaps, herein lies the distinction between Hume’s “philosophical terms” drawn from associations, which rely on repetition and have no necessary connection, and scientific knowledge which is gained by induction, and becomes clearer.