Appendix: Critique of Kantian metaphysics
Schopenhauer devoted the final section of the first volume to a thorough critique of Kantian metaphysics. The critique was intended in order to highlight the greatness of Kant and the quote by Voltaire said it all: It is the privilege of true genius, and especially genius who opens up a new path, to make great mistakes with impunity. Plato and the Hindu are the other intellectual muses, but Kant is the chief golden calf Schopenhauer genuflects before in the majority of The World as Will and Representation, but by the end of the book, he wields the hammer of Uru to clear away the rusty flakes. It is much easier to point out the faults and errors in the work of a great mind than to give a clear and complete exposition of its value. (WWR p. 415)
Interestingly, Schopenhauer often laments Kant’s decision to edit his great work, The Critique of Pure Reason, in an overreaction to the charges of naïve idealism. As explained in Book I, representation is compatible with Kant’s transcendental idealism, where the spatial, temporal forms are how the objects in experience are (re)presented, and the basic structure of the concepts we think and judge with and the category of causality are the reflection of the structure of our perception or concept of reality. Nonetheless, when Kant argued that transcendental idealism prevents us from having any knowledge of the thing-in-itself, Schopenhauer disagreed and insisted that our experience of willing is actually the mode of access to the nature of reality that complements our spatial/temporal/causal framework for representing objects.
The chief reason for the disagreement between Kant and Schopenhauer lie with their choices of method: Schopenhauer agreed with Kant to the extent that we do have transcendental knowledge of the fundamental conditions of experience, but did not share in Kant’s convictions that transcendental knowledge is dependent on transcendental proofs or arguments. That is why Schopenhauer says we are not bound by Kant’s conclusions about the limits of knowledge and advocated a more practical method that dances close to Hume’s empiricism and Husserl’s phenomenology where direct experience indicates a dual approach to understanding it: the representations of spatiotemporal objects, and the capacity to will. Kant’s method of discovering the fundamental principles of knowledge as a special sort of reflection is mistaken, for we can know this through direct and immediate scrutiny of our experience.
“An essential difference between Kant’s method and that which I follow is to be found in the fact that he starts from indirect, reflected knowledge, whereas I start from direct and intuitive knowledge. He is comparable to a person who measures the height of a tower from its shadow; but I am like one who applies the measuring rod directly to the tower itself.” (WWR I, p. 452-453)
Thus, Schopenhauer’s transcendental philosophy dispenses with transcendental proofs. Schopenhauer continues: “Philosophy, therefore is for [Kant], a science of concepts but for me a science in concepts, drawn from the knowledge of perception, the only source of all evidence and set down and fixed in universal concepts.” (ibid, p. 453) Once Kant abandoned the realm of perception, he errs magnificently especially when he insisted that all the abstract categories of logical theory must be present in our knowledge of objects.
The main charge Schopenhauer lies at Kant’s feet is the complete lack of any distinction between abstract and discursive knowledge and intuitive knowledge. (WWR I p. 473) Yet, later on Schopenhauer then criticizes Kant for making that very distinction. Recall the famous dictum, “Thoughts without content are empty; intuition without concepts are blind,” which means there is no possible cognition of objects unless the two are combined. Schopenhauer says Kant blundered by bringing “thinking into perception,” meaning an object is not perceived meaningfully until it is thought. Nevertheless, we do not think in order to see an object, for no reflection is required at all. Yet Kant actually says that the concept emerges spontaneously, not deliberately.
Schopenhauer is quick to dismiss Kant’s categories as a sham; given the sole function of the understanding is causality. Moreover, Schopenhauer argued that all twelve categories are reducible to causality. This seems problematic, for we cannot think about causality without the notion of substance. The thought of something being caused already includes a substance of some kind. We are also incapable of thinking of causality without the assumption that all substances must behave in the same way under the same circumstances. we cannot think of causality without having the notion of quality. One could argue that Schopenhauer did not reject the categories altogether, but instead he took causation as the function that connects separate perceptions of distinct objects, a function that conditions perception of objects. The categories or the capacity of making judgments is secondary to perception because they are aspects of reason, which is in itself entirely parasitic on the originary cognitive activity of perception.
Animals do have knowledge of objects via perception, despite lacking the ability of making judgments. Therefore the forms of judgments are structured by reflection, a secondary cognitive activity.
“Forms of categorical judgment is nothing but the form of the judgment in general,” i.e., the form of the abstract expression of the knowledge of objects, which is founded on perception. “Disjunctive judgments spring from the law of thought of the excluded middle… therefore entirely the property of reason.” (WWR, I p. 459) they show the basic form of the activity of comparing objects in the abstract. Schopenhauer concludes that all forms of judgments and the categories are the inherent structures of the activity of abstract thought.
To which Kant might’ve conceded that the expression of abstraction is secondary to perception of the object, but he would’ve argued that we are capable of making judgments because of the synthetic nature of our conscious perception of objects – that which forms sensations as well as the conceptual structure.
Schopenhauer’s most enduring criticism of Kantian philosophy is on causation. For Kant, the knowledge of the determinate temporal order of objective states of affairs depend on the knowledge of causal laws whereas for Schopenhauer, the knowledge of the temporal succession is independent of any such condition, because it is already immediately given. This issue about the relation between the phenomenology of our experience of temporal order and the transcendental conditions of our experience remains unresolved today.
The Kantian scholar Paul Guyer indicated three of Schopenhauer’s objections to Kant’s treatment of causality, that it marginalizes immediate perceptual knowledge for the sake of conceptual elements of the understanding:
1. The sequence of perceptions are events and our knowledge of the sequence of these perceptions cannot and do not depend on the causal laws that entails change in these represented objects.
2. The knowledge of the succession of states of affairs contain some earlier events that did not cause the later ones, so, the knowledge of succession does not depend on the knowledge of causality.
3. Kant’s treatment of causation: Schopenhauer said that if the knowledge of temporal succession wasn’t immediate, but actually depends on the knowledge of the laws that determine the speed and timing of those successions, then we must have nearly unlimited knowledge of the causal laws.
Guyer defends against the first two objections to rest on a misunderstanding of Kant’s argument, and a failure of distinguishing between the phenomenological method and Kant’s transcendental method. Nevertheless, he admits that a reconstruction of Kant’s position must deal with the aforementioned third objection.