Observing Phenomena “from the Outside”: Series and Order of Appearances

Hering’s demand that the terms, the concepts and the primitives of theory have to fit the characteristics of appearances also has great methodological impor­tance. Von Helmholtz’s theory is charged with bringing in unnecessary mental constructs because of insufficient description. The phenomenal component of perception is reduced to the sensory effects that are considered something material to process by the psychological activity, which is presumed to be pe­culiar to the mind. This account stems from the disputable classification that something is phenomenal only if it is directly derivable from physiological pro­cesses, otherwise it is mental or “psychological.” For this reason Hering dubs von Helmholtz’s theory a “mentalistic psychology” of perception that faces two complementary risks. Firstly, phenomena are not satisfactorily recognized as such, like the appearance of black, which is not interpreted as a full-fledged visual quality because it is the correlate of the absence of actual stimulation. Von Helmholtz is induced to account for it as the effect of the baseline activ­ity of retinal cells at rest. As a result of this spurious asymmetry among colors, the theory is forced into an analogy with no empirical and conceptual grounds (1878: 63, 65-66). The visual field of the occluded eye is assimilated to a mental blackboard on which light or some internal stimulation paints the white or the chromatic colors as well as erases them. The more thickly the colors are paint­ed on it, the lighter the white and the more saturated the colors are supposed to appear, hence the less the black of their background may shine through. Secondly, admitting mentalistic posits is equivalent to the methodological mistake of admitting the concept of vital forces to account for the mechanics of organic vital processes. As in the past, what was falsely believed to be due to vital forces turned out to be a physiological process, so an appearance that is believed to be due to the mind may turn out to consist only in phenomenal properties that maybe functionally explained by future findings of physiology (1878, I: 2).

Indeed, Hering (1878: 72-74, 80, 1905: 20) contends that for a theory of perception to be complete it has to be a physiological psychology. It is rea­sonable to suppose that perception has a physiological basis constrained by physical and chemical laws. Yet this hardly means dismissing phenomenology. The physiological theory of perception cannot be limited to dioptrics and to the study of histological and anatomical properties of the nervous system cor­related with perception. Moreover, it is not easy to obtain and assess the evi­dence on the functional physiological account of the nature and properties of appearances. Hering (1878: 4f.) recognizes the fundamental contribution of the “philosophical psychology,” that is, of the observation and the analysis carried out with “an empirical commitment” of appearances to abstract their features and forms of order. The correct description of phenomena has, of course, a heuristic function. As a mirror image gives information on the mirrored thing, so the evidence of the analysis of appearances give clues about which characteristics the physiological functions should have to underlie perception (1878: 4). The philosophical psychology also performs an epistemological func­tion. The physiological psychology provides the findings that make the expla­nation of perception complete. The phenomenological analysis makes sense of the physiological findings by its knowledge and evidence about the observ­able features of phenomena. The unbiased analysis of appearances allows for assessing the validity of the functional connection between physiological pro­cesses and appearances, thus contributing to an estimate of the likelihood of the success of a theory of perception.

Hering’s theory of color gives a clear example of the role of the analysis of color appearances in the science of perception. The analysis is phenomeno­logical, for it does not take the known or hypothetical causes of colors into account. It is required for an unbiased theory that is guided by the discovery of the self-sufficient features, relations and order of appearances. Hering points out that this request is the same for every science. Physics discovered the laws ruling the contribution of different wavelengths to a composite radiation af­ter specifying the relevant variables in the manifold of light radiations. Since radiation of a single wavelength is an extreme case, physicists had to discover the feature by which to compare the different wavelengths that usually form composite radiations and discover their order. Likewise, the relevant variables of color appearances have to be discovered, and colors themselves must pro­vide the decisive characteristic by which an order is imposed on their mani­fold mixtures. Instead of using physical and physiological measures as best gauges of phenomenal properties, Hering builds series of appearances that change into one another smoothly or through a definite series of connected transitions in order to observe the extent to which two neighboring colors differ from each other in a specified respect. The resulting observations are not inner intuitions or introspections. The design of the series allows for the suspending of reference to things, which goes along with the ordinary percep­tion of colors as independent properties, and observing the colors themselves “from the outside” (1905: 24).

If the research is limited to achromatic colors, the series of transitions goes from pure black to pure white. Hering remarks that these colors as such may not occur in ordinary experience, unless as actual colors whose appearances are a high approximation of perceptual pureness. Nonetheless, they have to be considered at the extreme of the series for their phenomenal function. Indeed, it is observable that all color appearances are similar under the respect of their distance along the direction connecting each member to the black and the white at the opposite ends of the series (see 1878: 52k, 1905, 23-62, for chromat­ic ordering series). The more distant colors are from black, the more they show a whitish trait in comparison to it. The more distant colors are from white, the more they show a blackish trait in comparison to it. Yet the grey appearance at the same distance from the black and the white ends does not appear to share a black and a white trait, but displays a distinct color quality. In grey appear­ances, the black and white values are somehow present but as if both were toned down in each case with a varying degree of distinction, that is to say the greys in the series have an independent chromatic quality. It is true that a similarity or difference in lightness and darkness goes along with the varying distance of grey from the black and white ends. Yet this is a kind of additional feature that derives from the opposite nature of black and white in the color order. Black and white share no apparent trait. They are opposite appearances whose conflicting difference rests on the fact that there is no degree of simi­larity between them. Instead, the greys are ordered through the variation of a chromatic quality that allows for degrees of similarity.

Hering demonstrates that this observation on the nature of appearances produces compelling test cases against competing theories. For instance, it justifies the objections against von Helmholtz’s account of black (1905: 29k). The phenomenal features of black appearances along the series are preserved even if one reverts von Helmholtz’s explanation as the absence of external stimulation. This is the evidence that the black color is an ordinary full-fledged visual quality whose discovery is essential for a correct physiological expla­nation (1878: 53k, 62k). On the other hand, the observation that the white appearances do not display any trait of other colors, while the converse is true, permits one to restrict the explanation of white as the composition of comple­mentary colors to physics. In fact, the relations among white and other color appearances induce to treat white as a self-sufficient species of perceptual quality that is instanced by simple color appearances, even though it can be phenomenally related to other colors in which it can be more or less clear­ly noticed (1878: 71). Finally, an example of the evidence based solely on the analysis of the phenomenal behaviour of the appearances is the separation of the black-white and the dark-light qualities into two distinct perceptual dimensions (1878: 51k, 76, 80, 83k). This evidence cannot be derived by the knowledge of the properties of the stimulation; hence, von Helmholtz’s theory that this series is a single dimension that corresponds to the variation of the intensity of light radiation is false. On the contrary, the observation shows that the single physical stimulation of the light intensity variation must be split into two distinct phenomenal dimensions. Black and white are both chromatic qualities. In the greys it is possible to see two distinct components: the chro­matic and the achromatic part. The relation between black and white brings about only the latter, because the ratio in which they are seen in grey deter­mines its lightness. This is clear for an unprejudiced observation of the series. The changes in the greys along this property do not fit the order of the series; hence, it must belong to another continuum. The phenomenological point is that the same appearances undergo independent variations along the black- white and the light-dark direction; hence, the series of grey cannot be reduced to the quantitative change of white caused only by the light intensity for which the black is simply equivalent to the absence of stimulation.

Source: Calì Carmelo (2017), Phenomenology of Perception: Theories and Experimental Evidence, Brill.