But to account entirely for the strangeness of our judgments about sensible qualities, it should be considered that the soul is so closely joined to its body and has even become so carnal since the Fall and consequently so incapable of concentration that it attributes to the body many things that belong only to itself, and hardly distinguishes itself from the body anymore. As a result, it not only attributes to it all the sensations we are now discussing but also the power of imagination and sometimes even the capability of reasoning, for many philosophers have been stupid and dense enough to believe that the soul is only the subtlest and rarest part of the body. (LO 57)
The precise relevance of this might escape the casual reader. As Malebranche sees it, the fundamental error involved in attributing the sensation of heat to the hand is that it ascribes to the body what is in reality a modification of the soul. He goes on to note that the soul “is so blind that it misunderstands itself and does not recognize the ownership of its own sensations” (LO 57). The real difference between pain and color is that they have different types of relevance to our preservation, not that one is in the sensory organs and the other is in the external object.
The heart of Malebranche’s discussion of this point is the close union between the soul and the body. In Malebranche’s view soul and body are united nomologically, i.e., God has instituted general laws in which soul-events and body-events are correlated. Because Malebranche is an occasionalist, this means that the soul-body union is as strong a union as any other union short of identity. If we choose to measure the strength of nomological unions by how close the established correlation is, Malebranche is fully able to argue that the soul-body union is very strong. The sort of general laws governing the union are instituted for the preservation of the body, and thus require that the soul be closely concerned with bodily matters. This, however, does not suffice for the phenomenon Malebranche identifies in the above quotation; the source of the error is not merely the strength of the union, but what follows from this strong correlation given original sin. This is what ‘carnality’ is intended to convey: the culprit is our pathological dependence on those soul-events that are correlated with body-events (e.g., sensations). Instead of taking these events merely as aids toward preserving the body, we treat them as if they gave knowledge of the bodies. This quickly involves us in the error of attributing sensations and even imagination and reasoning to bodies; this is closely related to the sort of error Malebranche thinks is involved in the case of idolatry, where, in Malebranche’s terms, we also attribute “the capability of reasoning” to bodies.
It is interesting to compare this to Descartes’s view in the Principles. Descartes notes that it is difficult for us not to go beyond what we clearly perceive in the case of sensations because “all of us have, from our early childhood, judged that all the objects of our sense-perception are things existing outside our minds and closely resembling our sensations” (AT VIIIA 32). He later explains these “preconceived opinions of childhood” by saying that in early childhood “the mind was so closely tied to the body that it had no leisure for any thoughts except those by means of which it had sensory awareness of what was happening to the body” (AT VIIIA). This is similar to Malebranche’s view in that the close union of mind and body plays a key role. From this point, however, they diverge: while Descartes appears to hold that the development of these “preconceived opinions of childhood” are due to the fact that children simply do not have the “leisure” for more accurate thinking, Malebranche holds that they are the result of carnality, our root tendency to idolatry. From the very beginning we develop these preconceived opinions not through lack of leisure but through a perverse fascination with sensible qualities that prevents us from recognizing the rationally available truth that the sensible qualities cannot be in bodies. Descartes does discuss a cause of error that is somewhat closer to Malebranche’s view than “preconceived opinions of childhood,” namely the “difficulty and fatigue” with which we attend to things that cannot be sensed (AT VIIIA 37). The very same differences are at play here, however; whereas Descartes attributes this difficulty and fatigue to the closeness of the mind-body union or childhood opinions, Malebranche attributes them to carnality.