Why Martin’s Disjunctivism is the Preferable Account of Naïve Realism

The Argument from Hallucination has persuaded many away from their pre-philosophical notions about veridical perception. Those who are seduced by the Argument from Hallucination do not believe that one ever has direct access to mind-independent reality. Naive realists resist this conclusion, defending common sense and arguing that mind-independent reality actually constitutes one’s thoughts in veridical perception. Mark Johnston and M.G.F. Martin are two such naive realists. Johnston defends naive realism by stating that cases of indiscriminability between hallucination and veridical perception can be explained by a shared feature. This shared feature is mind-dependent in the case of hallucination, but is instantiated by a mind-independent object in the case of veridical perception. Martin takes a different approach, arguing that there is no robust feature of hallucination. Hallucination’s only feature is its indiscriminability from veridical perception. Both Johnston’s and Martin’s views have their good and bad points, but I will argue that Martin’s view is the more philosophically tenable in light of the Argument from Hallucination and therefore that it should be the preferred defense of naive realism. Before one was tainted by philosophy, one believed that one had direct access to mind-independent objects. When one veridically perceived an orange water bottle, one might have said that the fact that one was seeing a mind-independent object is made manifest by the mere perception of it (though perhaps in less philosophical terms). The Argument from Hallucination questions this view. The Argument gains its potency by emphasizing the “bad cases,” the instances when a perceiver cannot tell the difference between mind-independent reality and a mind-dependent hallucination. Let us say that Sally, walking through the desert and water-deprived, notices what looks to be a well in front of her. The well appears to her as a mind-independent well would, seeming appropriately vivid and displaying well-like sensory characteristics. Sally thinks that she is seeing a mind-independent well but in reality is merely experiencing a mirage. The Argument from Hallucination asks why, if perceivers are mistaken about accessing mind-independent reality in some cases, one should ever assume one has mind-independent objects as unmediated constituents of one’s thoughts. From the Argument from Hallucination springs “perceptual bottleneck theorists.” These theorists, seduced by the Argument from Hallucination, believe that one never has access to mind-independent reality. For instance, sense-datum theorists believe that one only ever perceives mind-dependent sensory data, data that may or may not reflect external reality. So when Sally saw the mirage in the desert and when Sally sees a real well that is indiscriminable from her mirage, she is seeing the same thing. The sense data in the case of the mirage and in the case of the real well are the same. Sense datum theorists address the problem of hallucinations that are indiscriminable from veridical perceptions by arguing that in both cases one perceives the same thing: sense data. 1