Dwelshauvers

Dwelshauvers enters Jean-Paul Sartre’s account of mental imagery as an experimental psychologist whose research makes bodily movement central to the formation of images. His experiments support the claim that a mental image can arise from a muscular attitude that the subject does not consciously perceive; Sartre values this evidence but finds its causal explanation incomplete. The resulting portrait is not a biography but an intellectual role: Dwelshauvers supplies observations that Sartre tests against a phenomenological account of how movement, visual expectation, and imaging consciousness are joined.

Place in the Argument

Dwelshauvers is introduced within a discussion of the close relation between images and movement. Guillaume’s work had described the image as both a motor cause of movement and an element that controls it, while Dwelshauvers’s experiments were taken to suggest that images are accompanied by very slight movements, such as trembling of the fingers. Jean-Paul Sartre distinguishes these claims from the question he wants to pursue: not only whether images condition movement, but whether movement and kinaesthetic sensation help constitute an image in the first place.

That distinction gives Dwelshauvers’s research a specific argumentative function. His observations provide a route into the possibility that bodily activity can contribute to imagery without appearing to consciousness as an ordinary, consciously noticed sensation. Sartre does not simply repeat the experimental conclusions as an explanation. He uses them to pose a problem about how a motor process can become an image of something visually presented, while remaining different in quality from the muscular attitude that helped produce it.

Muscular Attitudes and Image Formation

Sartre cites Dwelshauvers’s experiments as evidence for mental images that are conscious translations of muscular attitudes. On this account, the subject does not perceive the attitude itself, yet an image appears in consciousness that differs from the bodily elements involved. The proposed sequence begins with an idea of a movement to be carried out. A muscular attitude then gives that motor intention an objective form, without the subject becoming aware of the reaction or posture as such. The image follows as a registering of that reaction, but is qualitatively unlike the movement that occasioned it.

The sequence matters because it separates bodily contribution from conscious content. The image is not simply a perceived muscle movement reproduced inwardly: the muscular attitude remains unperceived, and what appears is an image with a different character. Dwelshauvers’s experiments therefore support a distinction between the bodily process involved in genesis and the representational appearance that emerges in consciousness. They also sharpen the central question of Sartre’s discussion: how can the image be related to movement without being reduced to a kinaesthetic sensation?

Sartre’s Reservation About the Explanation

Jean-Paul Sartre accepts the experimental facts as significant but says that they have not yet been explained. He finds Dwelshauvers’s description of their operation unsatisfactory and undertakes to clarify the process rather than treating the report of a muscular attitude followed by an image as a complete account. The reservation is methodological as well as theoretical: an observed sequence establishes a phenomenon, but it does not by itself explain the structure through which the phenomenon becomes an image.

Sartre tests one possible interpretation by asking whether movement simply evokes an image. He rejects that formulation as inadequate. If the movement were to evoke the image while remaining unconscious, it would still have to subsist alongside the image as its cause. Yet, in the case under examination, the kinaesthetic impressions seem even less independent when the image appears than when they are masked by actual visual impressions. An attempt to recover those impressions is accompanied by the image’s disappearance. This makes the relation harder to describe as a simple stimulus-and-result sequence: the bodily impressions do not stand beside the image as an independently available source.

The problem is also not solved by calling kinaesthetic impressions substitutes for visual form. Sartre regards that proposal as obscure unless the mechanism of substitution is made clear. His objection does not erase the experimental finding that bodily attitudes can participate in image formation. Instead, it identifies what the finding leaves unresolved: the relation between a bodily process, the image’s visual character, and the object at which the image is directed.

Movement, Visual Form, and Sartre’s Reinterpretation

Sartre’s alternative account emphasizes that movement is apprehended through phases, not given all at once. Each impression belongs to a developing course of movement and is joined to what has just passed and what is expected to follow. Drawing on Edmund Husserl’s account of retention and protention, Sartre describes these acts as holding the immediate past and anticipating a continuation. In this framework, the movement’s successive states can be unified without being treated as a collection of isolated sensations.

When visual impressions are absent or weak, Sartre argues, they may nevertheless continue to regulate the apprehension of movement. He points to findings that people asked to trace two equal lines with their eyes closed guide themselves by visual representations of the lines’ endpoints. The proposed account is that retention can convert a just-past kinaesthetic phase into the visual form it would have had if seen; protention anticipates a coming visual sensation from the present content. The image’s visual character therefore cannot be explained merely by claiming that movement calls up a picture. Sartre instead proposes a distinctive conversion within consciousness, while acknowledging that this conversion itself requires phenomenological description.

A separate example clarifies the difference between a movement and the visual figure it can support. With eyes closed, a person tracing a figure of eight with the tip of an index finger does not simply experience a clear kinaesthetic shape. Sartre describes the emerging figure as a visual form in the process of being constituted, as though it could be seen at the fingertip if the eyes were opened. It may persist briefly after the movement stops, seeming to remain where the finger moved. These details make the image neither identical to the movement nor merely an after-effect that disappears with the last muscular sensation.

Scope and Significance

Dwelshauvers’s experimental work thus occupies an important but limited place in Sartre’s analysis. It establishes that mental imagery can be associated with muscular attitudes that the subject does not perceive and that the resulting image differs qualitatively from those attitudes. Sartre’s discussion preserves that distinction while resisting the idea that the image can be explained by an unconscious movement simply provoking it. The experiments open the question; they do not settle the phenomenological account of how bodily movement becomes visually imaged.

The same inquiry extends beyond clearly formed images. In discussing the Würzburg school, Sartre cites Burloud’s reports of poorly differentiated motor representations accompanying thought: shifts of attention, movements of the head, pressure of the jaw, and uncertainty in the hands or posture. Subjects may be unable to tell whether these are sensations of an attitude or representations of movement. This material does not constitute a further finding by Dwelshauvers, but it places his experimental problem within a broader zone of experience where movement, knowledge, and imagery are not cleanly separated. Dwelshauvers’s significance in the chapter lies in making bodily contribution experimentally visible, while Sartre’s analysis asks what kind of consciousness that contribution entails.