Prompt: Despite agreeing on certain points regarding the nature of sensory experience, Hume and Russell disagree on whether such experience affords a solid rational foundation for believing in the existence of external objects—with Hume adopting a skeptical position, and Russell arguing against such skepticism. Compare and contrast Hume and Russell on this issue, paying particular attention to the reasoning that leads them to their respective conclusions. Finally, critically evaluate the debate. Whose view, Hume’s or Russell’s, do you find more credible, and why? Argue for your position.
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A major concern in the field of epistemology revolves around whether our sense perceptions (sight, sound, touch, etc.) provide any rational basis for believing in external, mind-independent objects. We only ever experience sensory impressions of objects, and yet we believe in physical objects existing independently of our perceptions; this creates a justification gap between experience and theory. Both David Hume and Bertrand Russell agree that our senses do not acquaint us directly with external objects and that our sensory impressions are fleeting. However, they arrive at contrasting conclusions about the external world. While Hume adopts a skeptical view denying that there are any rational grounds for believing in external objects, Russell attempts to preserve realism and reconstruct a rational foundation through inference to the best explanation. This essay will argue that Russell’s position, though not free of difficulties, offers a more credible and plausible account of why belief in the external world is rationally defensible, striking a balance between skepticism and realism.
To understand the disagreement between Hume and Russell, it is helpful to begin with Hume’s position and the reasoning that leads him to his skeptical conclusion. Hume establishes two assumptions that underlie our belief in the external world: first, that objects possess a continued existence even when they are not present to the senses; and second, that they have a distinct existence, independent of the mind and its perceptions. His central claim is that neither assumption is rationally supported by our sensory impressions. From this, Hume concludes that we have no rational grounds for believing in the independent, enduring existence of external objects.
Hume first argues that our senses cannot establish the continued existence of objects beyond perception, because this contradicts the nature of our sense impressions. Sensory impressions are fleeting and intermittent, lasting only as long as the sensation itself. For example, the perception of a pencil will only endure while we touch it, see it, etc.; once the sensation ceases, so does the impression. Since sensory information itself has no continued existence beyond the moment of consciousness, it is incoherent to suppose that our senses could give us evidence of an object’s continued existence.
Turning to the distinct existence of objects, Hume considers and rejects two possible explanations. The first is the representationalist view, which claims that we are aware of mental representations that correspond to external objects. Hume contends that this view is circular, because it presupposes the very thing it seeks to prove. To say that our perceptions “represent” something already assumes the existence of external objects for them to represent. Thus, representationalism smuggles in the notion of a “double existence” of both the perceptions and their external counterparts. As Hume states, “a single perception can never produce the idea of a double existence” (Hume, p. 2). In other words, if all we ever experience is the perception itself, there is nothing in that experience that justifies belief in an independently existing object.
Hume also rejects the alternative view that perceptions themselves are external objects and that there is no distinction between the idea and the object. We recognize sensory impressions as internal to our consciousness by nature, so to treat them as external would involve some kind of “fallacy and illusion” as Hume puts it. Moreover, to perceive something as external supposes the distinction between the perceiver and what is perceived in order to recognize that something is outside of our consciousness. To do this, however, requires appealing to sense impressions of the body that are also fleeting and intermittent. This produces another circular attempt to use sensory experience to justify how other sensory impressions can appear external to the mind.
On the basis of these arguments, Hume concludes that sensory experience cannot rationally justify belief in either the continued or distinct existence of external objects. He adopts a form of committed skepticism, but with an important caveat; Hume observes that even after recognizing the philosophical weakness of our belief in the external world, ordinary life compels us to act as though external objects exist. He argues that the source of this belief is psychological and a product of habit rather than rational. For Hume, the notion of an enduring, mind independent object is just a projection of our imagination. To summarize, his stance is a form of psychological realism without epistemological justification: we must accept that our belief in an external world is both irrational and yet inevitable.
On the other hand, Russell seeks to show that the belief in external objects can be rationally defended. Like Hume, he begins with the observation that we are directly acquainted only with sense-data, not with the physical objects themselves, but argues that this does not need to lead to skepticism. Russell adopts a scientific approach to the problem, outlining two competing hypotheses: Hypothesis (1) — our sense data generally derive from external objects; Hypothesis (2) — only I and my private sense data exist. If there are rational grounds for favoring Hypothesis (1), then we do not have to be skeptics about our knowledge of the external world. This approach uses the method of inference to the best explanation, where inferences are made from the available evidence to the hypothesis that would, if true, best explain that evidence.
To support Hypothesis (1), Russell first appeals to the shared experience of other people. For Russell, the fact that we live in a common world and that various people can experience similar sense-data at different times suggest the existence of permanent physical objects that underlies or causes that sensory experience. Of course, this faces a similar challenge raised by Hume that we cannot rely on the testimony of other people because the testimony itself relies on sense-data. If we are not convinced that our sense-data reveals external objects, we can’t be convinced that sense-data reveals other people. As Russell notes, referencing Descartes’ Dream Argument, “I should have no reason to believe that other people exist as part of my own dream.” (Russell, p. 33)
Russell then argues that the physical world is the simplest explanation for the patterns and continuity in our sensory experience. For instance, a cat moving from one part of a room to another when we are not observing it, or that it gets hungry during certain times of the day, is best and simply explained by the fact that there is a physical cat independent of our perceptions. Russell argues that “every principle of simplicity”, or Occam’s Razor, compels us to adopt the common-sense view that there are objects other than ourselves and our sense-data. He further responds to Descartes’ Dream argument by noting that while dreams can produce false sense-data, they reflect and are influenced by the waking world, thereby indirectly supporting realism.
Returning to the initial hypotheses, Russell acknowledges that Hypothesis (2) – that only private sense-data exists – is not logically impossible. However, it is far less simple than the hypothesis of an external world. Given that the belief in the external world doesn’t lead to any difficulties and in fact simplifies our account of our experiences, Russell concludes that while we cannot directly perceive external objects, the hypothesis of their existence is the simplest, and most coherent explanation of our sensory experiences. Hence, our belief in external objects can be rationally justified if understood in explanatory rather than purely empirical terms.
Having outlined both positions, it becomes clear that Hume and Russell share common starting points but diverge significantly in their philosophical conclusions. Both acknowledge that we do not perceive external objects directly; instead we are only acquainted with sense-data. Both also agree that our belief in an external world is instinctive and unavoidable. Yet the philosophical significance they assign to these points differ sharply. Hume sees the gap between impressions and external objects as unbridgeable, and any attempt to cross it risks falling into circularity or contradiction. His epistemic strictness leads him to deny that we have any rational foundation for believing in a mind-independent world, even though we cannot help but believe in them in ordinary life. In contrast, Russell interprets the same gap as an opportunity for explanatory reasoning. He presents a scientific framework to the problem, in which the hypothesis of a physical world provides the simplest and most coherent account for the order, regularity, and shared agreement of our experiences.
This divergence reflects a deeper difference in their conceptions of the aim of philosophy. For Hume, philosophy serves as a skeptical critic: its task is to expose the rational shortcomings in our belief system, even if those beliefs cannot be discarded. Russell, on the other hand, sees philosophy’s purpose as offering rational support for our fundamental beliefs. Since we cannot abandon our instinctive commitment to an external world, Russell argues that philosophy should seek to understand and rationalize this commitment rather than merely criticize it. These contrasting philosophical orientations ultimately lead Hume and Russell to their fundamentally different conclusions.
Both Hume and Russell offer influential accounts to the epistemic status of our belief in the external world, and each position has its strengths and weakness. Hume’s analysis has the advantage of uncompromising philosophical rigor: he exposes the limits of our sensory experience and shows that neither the continued nor distinct existence can be justified by reason alone, no matter its effect on our fundamental belief system. Hume’s conclusion, however, is a deeply skeptical one, to the point where he admits that no human being, even the most skeptical philosopher, could consistently live by it. This tension, between what reasons allows and what human nature compels us to believe is a defining weakness of his view, making Hume’s view epistemically self-undermining and the role of philosophy internally unstable.
Russell, by contrast, adopts an explanatory and scientifically informed method. Russell provides a positive epistemic framework, rather than simply diagnosing the limits of reason. This is, by far, the most compelling aspect of Russell’s position: it acknowledges the inevitably of belief in the external world while offering a method for rationally preferring realism to skepticism. Russell’s explanatory realism avoids the stalemate created by Hume’s committed skepticism, offering a more philosophically satisfying reconciliation between human nature and rational justification.
Several additional considerations strengthen Russell’s position. First, instead of demanding direct concrete proof of external objects, he turns to inference to the best explanation, arguing that the existence of the physical world is the simplest and most coherent account of our sense-data. Furthermore, Russell’s framework coheres with scientific practice. Modern science presupposes the existence of stable, mind-independent objects that Hume’s strict skepticism cannot rationally justify. Although Russell’s explanation is not immune to all doubts, he maintains that it does defeat skepticism, and is sufficiently strong enough to place the non-skeptical belief in an external world on a more firm and more rationally defensible ground than Hume’s skeptical alternative. For these reasons, Russell’s account is more persuasive; it accommodates the instinctive belief in external objects and situates it within a coherent, explanatory framework that meets plausible standard of rational acceptability.
The contrast between Hume and Russell reveals two distinct ways of confronting the epistemological challenge posed by sensory experience to the external world. Hume’s strict empiricism exposes powerful limitations in the attempt to justify belief in external, mind-independent objects, ultimately yielding a form of skepticism that showcases the tension between the inevitably and irrationality of such belief. Russell, on the other hand, shows that although absolute uncertainty is unattainable, the hypothesis of a physical world offers the simplest, most coherent explanation of the continuity and shared nature of sense-data. By integrating scientific reasoning, and inference to the best method, Russell provides a framework that seeks to understand rationalize this fundamental belief that not only avoids the self-undermining implications of skepticism, like Hume’s, but also aligns with the practical commitments of ordinary and scientific life. To conclude, Russell’s realism rests on a firmer and more philosophically productive grounds than Hume’s skeptical critique, and consequently, the belief in an external, mind-independent world emerges as the more credible view.