Christian Wolff: Rational psychology (1734)

I have a feeling that the meaning of the epithet ”rational” in Wolff's Psychologia rationalis has not been generally understood. Wolff does not want to express his dedication to some rationalist school of thought, but merely points out that he wants to give ratio, reason or explanation to empirical data presented in his empirical psychology: we know what our soul does, now we will see why it does that.

Due to suspicions that the central ideas of the rational psychology lead somehow to atheism and mechanistic philosophy, Wolff is quick to point out that nothing in his later philosophy – especially in theology and ethics – hinges on the explanations of rational psychology, but only on the data given in empirical psychology (I have a hunch that he might have actually transferred some of the statements in the former to the latter, in order to make this explanation more convincing). Rational psychology is then rather unexpectedly a field of philosophy that has no use in other fields of philosophy, but serves only as a path to greater understanding of oneself by showing things that we could not directly observe of ourselves.

The primary fact that rational psychology should explain is self-consciousness. Self-consciousness, Wolff begins, is not just some murky feeling of oneself, but instead, distinct perception of oneself. That is, when one is conscious of oneself, one is able to distinguish oneself from other things. This requires that in self-consciousness one must be able to concentrate attention on oneself, but at the same time remember what other things one had perceived in addition to oneself.

Yet, as I have noted earlier, Wolff wants to go even further and not remain in the level of empirical details. He crosses the line of what Kant would approve and purports to prove that soul cannot be material, because material complexes cannot represent anything as a unity, which would immediately disprove the existence of self-consciousness. I have already discussed the weaknesses of this argument, thus, I can move to Wolff's discussion of what the soul should then be like.

If soul cannot be material complex, it must be one of the simple entities, which in Wolff's ontology were argued to be forces. Question is then what sort of force should be on base of all the phenomena occurring in soul. Wolff notes the obvious fact that whatever soul does, it always views of represents the world. Of course, it does not represent the whole world perfectly, but only from a certain vantage point: during dreamless sleep, soul has only obscure representations, and even while awake, its representations are conditioned by the place of its body in the world and the condition of this body. Still, Wolff insists, we could say that the basic force of soul is one of representation.

I have criticized Wolff's answer of circularity and this was one point the pietists attacked also: how can one pick out representation as the essential ingredient of what it means to be a soul with no other justification, but the obvious fact that soul happens to represent? Wolff's answer appears to have been that representation was not meant as the only feature of the essence of soul, but merely as one central ingredient, out of which all the other central ingredients could be found. If we accept this explanation, Wolff still has to show how all the other faculties of human soul can be derived from this central force – that is, he has to show that they can be interpreted as mere modifications of the force of representation.

In case of cognitive faculties this derivation appears simple. Sensations clearly represent objects in the world or at least the modifications these objects cause in the sense organs of the body. This does not mean that sensations should present a perfect picture of the world. Indeed, only those features of sensations could be said to represent things, which happen to resemble the things, that is, Wolff insists that only traditional primary characteristics like number, motion and figure represent anything. Furthermore, not even all primary characteristics are faithful representations, according to Wolff, for instance, we sense a continuous space around us, although everything in the physical world must consist of a distinct and non-continuous, individual points of force. And of course, if some harm happens to sense organs, the corresponding sensations become more obscure or even completely vanish.

While sensations are clearly representations of objects actually present, phantasms of imagination are representations of objects that we have sensed, that is, they are representations of past, or at least they are recombinations of past sensations. Similarly, intellectual faculties are representations of features shared by several objects.

Cognitive faculties are then quite naturally just representational for Wolff. Furthermore, they all have a close relationship with body. This is obvious in case of sensations, because we cannot have any sensations without sense organs. Still, Wolff goes a step forward and suggests that there is something resembling the sensations in our brains: material ideas Wolff calls them. The point is understandable in case of vision, because contact of eyes with light produces an image, which might then be transferred to brain. Clearly Wolff wants then something analogical to hold with other senses.

Wolff suggests that material ideas of perceived objects remain in the brain, but after a while they start to lose their vividness, unless reinvigorated by new sensations. These afterimages of sensations are then the physical counterpart for the phantasms of imagination. But at the level of intellectual faculties the correspondence of soul and brains ends: concepts are distinct perceptions and thus involve also self-consciousness, which Wolff just had declared to be impossible to represent materially. Despite this, Wolff admits that the brain at least has material ideas of words necessary for articulating the thoughts.

The correspondence between body and soul raises then a natural question whether it refutes the 

supposed liberty of human actions – a common complaint against Wolff's philosophy. Indeed, human body follows the laws of physical universe. Changes in human soul and especially its sensations correspond with some changes in human body. Thus, it appears that sensations particularly follow their own laws, and because other cognitive faculties, like imagination, are based on sensations, they too must have their own laws. Wolff goes even so far as to suggest that one can define what is natural for human soul on basis of these supposed laws – and just like in case of physical universe, one might define supernatural or miraculous in terms of what is against such laws.

Wolff still supposes that these laws of sensation and imagination leave room for human liberty. Thus, although I cannot just by wishing make an object send to me different sensations, I can, for instance, change my spatial setting and look at a different object. Clearly this is not enough to guarantee human liberty, but I shall return to the topic in a later text, when speaking of the different ways to explain the correspondence of body and soul.

In any case, the important result Wolff thinks he has established is the reduction of all cognitive faculties to representational force. This still leaves open the question whether appetetive faculties can also be so reduced – this shall be the topic of my next post.