1. Introduction

The essay focuses on the Humean discussion of the vulgar system and philosophical system. He introduces these two systems to evaluate why there can be, or why one should believe in, the opinion of a continued and distinct existence of an object. This essay intends to evaluate the arguments by Hume first through a reconstruction of his claims, and secondly discussions of other scholars, specifically Pears and Mackie, who criticize or disprove his systems and evaluate their validity or functions. It also includes a few thoughts on whether these criticism are valid enough to dispute Hume’s analysis and his skepticism position.

2. Continued Existence

Hume observes that there can be an opinion of the continued and distinct existences of this object. “Continued” means even when the object is not present in the normal senses, one may still attribute an existence to it; “distinct” means the existence is independent of perception [1]. Since these two existence are connected, Hume focuses his discussion on one issue: How does one attribute a notion of continued existence to an object that is no longer present in the senses? [1]

The opinion of a continued existence can only come from the faculties of the mind: senses, imagination, and reasoning [1]. Senses can only contribute to a present perception and nothing more. Otherwise, other faculties of mind are involved [1]. Reasoning also cannot explain the continued existence. Since this opinion is deduced from a perception of an object, the only possible kind of reasoning is causation [2].

However, causation can only operate based on past experience, or custom, which consists of the repeated relations between two perceptions [1]. There cannot be deduced a continued existence of one object based on its perception, since it is uncertain whether the object will be observed again [1]. Therefore, the only possibility is that the opinion of a continued and distinct existence of an object arises from imagination, or more specifically, “a concurrence of some of their (the existences’) qualities with the qualities of the imagination” [1, 2].

3. Imagination

During his discussion of imagination, Hume starts his systematic analysis of the two system, which he calls “the vulgar system” and “the philosophical system”. The main distinction between the two systems is that the vulgar system does not distinguish perceptions from objects, while the philosophical system does [1, 3]. Hume believes human understanding often starts with the vulgar system. However, since it does not differentiate perceptions from objects, when it is observed that a perception interrupted, the problem arises: it does not hold that the two perceptions before and after the interruption as the same. Though they may seem extremely similar, Hume believes that they cannot be the same since human senses are interrupted and thus one perceptions is annihilated and another is created [1, 2].

Nevertheless, it is the resemblance that leads human imagination to attribute a continued existence to the gap [1]. When a person observe an object continuously, they observe a perfect identity. Though strictly speaking, time would imply succession and thus the identity will not be perfect. [1]. Therefore, when perception is interrupted and the following perception resembles it, the person tends to attribute an identity to these perceptions. There arises a contradiction: the interruption and perishing of the perceptions and the identity the person attributes to them. Hume believes that the imagination has a natural tendency to ease the contradiction and thus creates a continued existence of the unobserved object. Since the force and vivacity of the impressions are transferred, according to Hume, the person develops a belief in the continued existence of an object when it is not observed [1, 2].

It needs to be noted here that Hume elaborates this explanation of imagination based on the vulgar system, which confounds perceptions with objects, and thus fails to understand that it is the belief that allows people to have a opinion of the continued existence to maintain the identity of objects or perceptions, even when they are unobserved [2]. This fiction, however, is clearly unacceptable to Hume, as well as other philosophers, who attempt to solve the contradiction between the supposed perfect identity and the interruption of perceptions through another system [1]. Therefore, they develop a system of double existence, in which “the former [the perceptions] are suppos’d to be interrupted, and perishing, and different at every different return; the latter [the objects] to be uninterrupted, and to preserve a continu’d existence and identity” [1]. Hume deems the philosophical system as one more convincing than the vulgar system since it does not cover the issue of interrupted perceptions with imagination [3].

However, Hume still observes flaws in the system: the belief of continued existence of the objects cannot be explained through reasoning or imagination [1]. The following is a crucial claim of Hume regarding the philosophical system and its double-existence theory: a person cannot observe a causal relation between perceptions and objects, because the latter is never present to us. Reasoning is thus ruled out [1]. If imagination is once again called upon, this resorts to the same recourse of appealing to the foundation of the vulgar system, since it is impossible to conclude from the interrupted and varying perceptions alone, which are based on the same object, and imagine a continued, distinct and uninterrupted existence [1].

In conclusion, Hume thinks both systems rely on imagination to explain the opinion of a continued and distinct existence, though the philosophical one still fails to establish a grounded relation between perceptions and their corresponding objects. There is often a tendency to use the vulgar system to think about perceptions.

4. Reflections on the Two Systems

Based on Hume’s analysis, there can be further reflections on these two systems and whether Hume’s assertion is valid. One issue that constantly draws the attention of scholars is the vulgar system, which does not seem like an applicable system, even to the uneducated [3]. It would be easy for anyone to recognize the differences between perceptions and objects, even though they might not develop a complicated philosophical system to explain those phenomena regarding the differences between the two. For example, if a person put their finger close between their eyes, they will be able to experience double vision and with little reflection, they will conclude that it is the perception that changed, not the finger itself. Therefore, if the claim of HUme is taken literally, it would be difficult to imagine someone who will not notice any difference between the perceptions and the objects and continue to believe they are the same thing.

Pears further provides a rather radical version of criticism against the vulgar system [3, 4]. He claims that even when Hume confines his analysis to the vulgar system, he still assumes a double existence of perceptions and objects. Suppose that, in a vulgar system, senses are temporarily compromised and individuals are forced into a senseless state, or an interruption. In this kind of state, why would these individuals perceive the interruption as a continued existence rather than a complete void?

For Pears, the most crucial problem of this objection is that, when the vulgar system allows people to believe a complete void, it discredits the idea of space in this system [4]. Indeed, Hume claims that in the vulgar system, some impressions are deemed external [3]. He states that the “figure, bulk, motion and solidity” of objects are regarded by both systems to have continued existences; the “colours, tastes, smells, sound, heat and cold” only by the vulgar; and “the pains and pleasures, that arise from the application of objects to our bodies” by neither [1]. Therefore, the objects outside human body can be considered spatially external. From the viewpoint of Pears, however, this is against the basic assumption of the vulgar system [4]. If one cannot have a perception of space, one cannot distinguish between oneself and what is external to them. Therefore, according to Pears, one who lives in the vulgar system inevitably has experience radically different from what people possess [4]. For example, he may not have the notion of physical bodies and spatial relationships and he may have to suppose that the objects are “godlike existence, without bodies” [4].

Furthermore, it indicates that one can not distinguish changes caused by oneself from those caused by the observed objects. Suppose a person leave a room with a fire on, according to Pears, it is implausible to speak of the person having a spatial movement and that their perceptions have changed, but having to say that their perceptions are “replaced by other, very different impressions” [4]. Therefore, though Hume attempts to evaluate the question of why the perception (of the fire) can be attributed a continued existence when one no longer observes it in the vulgar system, he has already presupposed a philosophical system with the double existence. In other words, Hume’s question of the opinion of the continued existence will effectively be based on a distorted system with no evidence or theories to support it. If he intends to present this issue and his analysis of it, Pears claims, he will have to reexamine this system [4].

5. Vulgar System and its Troubles

However, it should be noted that Hume does not believe the vulgar system is a well-grounded one, but one used by children, non-scholars, and almost all human beings when they have yet to form a sound philosophical system. Indeed the assessment of Pears indicates that Hume is oversimplifying the vulgar system and its implications, but it does not prevent Hume from claiming that the vulgar system is still a problem of the philosophical system, since his essential claim is that the philosophical system relies on the vulgar system to construct its own belief of continued existence [4]. Otherwise, it would not be difficult to explain how people develop the belief of a continued existence based solely on the interrupted and varying perceptions.

It may be possible therefore think of the vulgar system as a “gap” in the philosophical system. Whenever a person attempt to establish a relation between perceptions and objects, they have to rely on the vulgar system, or it is implausible for a person to have any knowledge of the object itself. Essentially, it is a system accepted by most as a presupposition, but Hume has proved it to be a false one [2].

This is the issue Mackie sets out to solve [5]. Namely, if a person want to establish a causal relation between perceptions and objects, they will have to prove the objects are real, instead of a logical construction. Inevitably, they will have to accept the vulgar system, or what he called naive realism, which has been proved wrong by Hume.

Mackie deems that the solution to this issue lies in how people construct their hypothesis. In the view of Hume, they need to first prove the objects as real beings or that they are indeed represented through the perceptions, and then move on to prove their causal relations. However, Mackie claims that this is merely their “order of acquisition, not the order of the justification” [5]. In other words, the first issue may come first in a statement, but they can both be proved together as “joint parts of a systematic explanatory hypothesis” [5]. These two claims are conjunctively provable in one hypothesis and avoid presupposing a naive realistic view to examine the issue.

The validity of this hypothesis lies in its simplicity. For example, people tend to prefer the Copernican hypothesis of planetary cycles over the Ptolemaic one, because the Copernican one requires less coincidence for it to be valid. “The elimination of unexplained coincidence” is a foundational guide for choosing between scientific hypotheses and Mackie claims that it can be applied to the philosophical theory [5]. Thus, it may be possible to reach a conclusion on a causal relation between the objects and their perceptions.

However, neither the elimination of unexplained coincidence nor a systematic explanatory hypothesis are conclusive evidence to prove the causal relation between perceptions and objects. Therefore, Hume is not likely to accept this theory and he does have good reason to remain his skeptical position [2]. Neither Pears and Mackie provides a conclusive argument to counter Hume’s position, though those who are not committed to skepticism might find Mackie’s system to be persuasive enough.

6. Conclusion

This essay has explored the analysis by Hume on his proposed theory of the vulgar and philosophical systems concerning the belief in continued and distinct existence. This analysis was accompanied by criticisms from Pears and Mackie. Hume demonstrates the reliance of both systems on the imagination to bridge the gap between interrupted perceptions and the notion of continuous existence. On the other hand, the critique by Pears exposes the inherent contradictions within the Humean portrayal of the vulgar system. It reveals the implicit reliance of the system on a double existence. However, this critique does not invalidate the central claim in Humean philosophy that belief in external objects lacks a firm rational foundation. The proposal of Mackie of a systematic explanatory hypothesis offers a more compelling alternative by suggesting that the existence of external objects and their causal role in perception are justifiable through a unified explanatory framework. While this approach may satisfy those inclined towards realism, it does not provide the conclusive proof that Hume demands. Therefore, while Pears and Mackie offer valuable insights and alternative perspectives, they do not definitively overturn the skeptical conclusions reached by Hume.