Present essay addresses the issue of interconnection between Hume’s skepticism and Kant’s critical philosophy through the prism of argumentation, Kant puts forward in his Prolegomena to Any Future Metaphysics and Critique of Pure Reason, designed to overcome Hume’s doubt about the potential of human cognition.
The thesis is defended that Kant’s argumentation simultaneously proceeds from Hume’s doubt and overcomes it in completely new theory, offering original interpretation of human cognition. Before addressing this particular argumentation, one should outline general philosophical orientations of both discussed philosophers.
Humean and Kantian philosophies
Hume’s philosophy may be situated in the wider tradition of English critical empiricism, which opposes idealism and scholastics in their trying to perceive outside world using logical categories and notions of subjective or objective spirit. In contrast, Hume contends that the mind should not be regarded as the source of logical determinations, because it lacks unity and is filled by contingent impressions and sensations. Hume also debunks causal determinism, arguing that people can not prescribe any causal ties between events on the basis of logical laws and notions, because no predefined logic exists. Hence, the only thing, which allows us making causal connections, is habit, created by the repetition of similar situations.
Hume also criticizes the notion of substance, which was dominant in then existing philosophy. According to Hume, the notion of substance is visionary because the object it describes can not be perceived through sensual impression – hence, it only represents the artificial connection of different qualities.
Kant’s project of critical philosophy is based on defining the limits of rational cognition. The purpose of critique of the pure reason is to define basic preconditions for objective cognition. According to Kant, rational cognition is premised on synthesizing pure notions of human mind with sensational material of the outside world to find it basic causal ties and laws. However, Kant argues that such cognition is in essence subjective, because it depends on specifically human mind and sensations, which are different from the objects, which they appear in themselves (in sich) (Ariew and Watkins, 45-47).
Moreover, based on these contours of critical philosophy, Kant claims that such ‘eternal questions’ of metaphysics as the existence of God, the issues of moral behavior, free will, eternal life, soul etc. should be excluded from the problems of objective cognitions and redirected to practical reason, which sets rules of behavior, rather than discovering the laws of universe.
Based on the discussed philosophical starting points let us discuss Kant’s argumentation.
Kant directs his critical potential against Hume’s doubt about the possibilities of rational cognition in §§ 27-30 of Prolegomena, where he says that “here is now the place to remove the Humean doubt from the ground up” (Kant, Prolegomena, 63).
Hume’s doubt as it was noted above derives from his skepticism concerning the possibilities of logical explanation of causal ties between different objects. Kant argues that such doubt is reasonable, however, in contrast to what Hume made, the solution to the problem of cause and effect lies not in habitual experience, but in rational constitution of subject, which forms the experience.
In other words, Kant reconfigures the problem, stating that out experience of causal relations between things is constituted by the a priori synthetic notions of reason (Kant, 64). In the same vein, based on his new theory Kant argues in the Preface to the Critique of Pure Reason, that Hume skepticism concerning cause and effect in fact denies the entire algebra and geometry which are based exclusively on a priori concepts and spatial-temporal synthesis (Kant, Critique of Pure Reason, 34).
In this way, it may be said that Kant’s argumentation proceeds from Hume’s skepticism concerning metaphysical dominance of determinism, but unlike Hume, who deduces cause and effect from experience, Kant shows that the experience is formed by the a priori rational concepts.
Kant conceptualizes his philosophical move in his famous questions: ‘How are synthetic a priori propositions possible?’ (Kant, 28). Kant argues, that the issue of cause-effect connection constitutes partial problem as far as pure reason consists from the number of a priori concepts, which, however, should not be deduced from experience.
Addressing Hume’s idea, that casual connections are derived from experience, Kant argues that, “Appearances certainly provide cases from which a rule is possible in accordance with which something usually happens, but never that the succession is necessary; therefore, a dignity pertains to the synthesis of cause and effect that cannot be empirically expressed at all, namely, that the effect does not merely follow upon the cause but is posited through it and follows from it.” (Kant, Critique of Pure Reason, 125).
It is evident that Kant’s critique of Hume’s doubt is based on clear understanding that cause-effect dichotomy is based on the category of necessity, which can not be derived from experience.
There is no denying the importance of the fact, that there is no guarantee that things and events, which habitually are understood as having casual ties, may accidentally lose their properties and casual relations. In this way, habit should not be regarded as the source of causal relations.
In contrast, casual relations are given necessity through a priori sensational concepts of space and time, which help analyze the relations between things and events and prescribe them certain casual ties and relation.
Therefore, it may be said that Kant’ s resolution of Humean doubt in this respect seems to be logically coherent, because in fact the repetition of events does not provide us with guarantee that there exist rational logical ties between them. Kant’s resolutions of the Humean doubt also helps defend our initial thesis.
Indeed, Kant proceeds from Humean skepticism and overcomes it in the new critical theory, designed to delimit the terrain of rational cognition. The latter idea may be proved by Kant’s own words in the Preface to Prolegomena to Any Future Metaphysics, where he argues that, “it was the remembrance of David Hume which, many years ago, first interrupted my dogmatic slumber and gave my investigations in the field of speculative philosophy a completely different direction.” (Kant, 10)
Kant’s conceptualization of cause-effect dichotomy as derived from a priori concepts is based on the critique of the real interconnection between cause and effect. Kant showed that cause and effect are distinct events, which can not be deduced analytically. Using his famous example, “A body A is in motion, another B is at rest in the straight line [of this motion]. The motion of A is something, that of B is something else, and, nevertheless, the latter is posited through the former.” (Kant, 240).
Hence, Kant arrives to the conclusion that the relation between cause and effect is synthetic, which means that it is derived from a priori sensational intuitions of time and space and a priori concepts of the reason, which unite distinct events and processes by means of prescribing to them necessary qualities.
Synthetic judgments are based on creating new knowledge about reality rather than discovering existing properties by means of analysis. In this way, understanding of the interrelationship between cause and effect is creative activity.
As it was noted above, Humean solution to the latter problem differs from Kant’s one in several important respects. Hume argues that, “I shall venture to affirm, as a general proposition, which admits of no exception, that the knowledge of this relation is not, in any instance, attained by reasonings a priori; but arises entirely from experience, when we find that any particular objects are constantly conjoined with each other.” (Hume, 27)
There is no denying the importance of the fact, that Humean interpretation is characterized by the essential flaws.
First of all, Hume’s empiricism seems to contradict his general skeptical starting point. Hume debunks dominant idealistic logical categories of cause and effect, however at the same time universalizes empirical supremacy of habit as the sole source of finding casual relations between things.
Humean argument ignores the universality of judgments relating to casual interconnections between certain processes and events. Mere habit does not guarantee objective necessity of casual relations and hence, can not be conceptualized as the source of empirical judgments about them.
Empirical sensations are characterized by subjective nature and as it was noted by Leibniz and Kant, often distort genuine properties of things. Therefore, it is obvious that sensations and impressions should not be conceptualized as the sources of cognition without a priori analytical and synthetic concepts, discovered by Kant.
Moreover, Hume limits his critique of metaphysics to the concepts of cause and effect, however, there is no denying the importance of the fact that the mentioned realm of philosophy includes other important problems, characterized by dogmatic speculation, ignoring empirical experience.
Kant’s resolution of Humean doubt is multifaceted and is not limited to the abovementioned argumentations. For instance, in § 29 of his Prolegomena Kant introduces distinction between ‘judgments of perception’ and ‘judgments of experience’: ‘Empirical judgments, in so far as they have objective validity, are judgments of experience; they, however, in so far as they are only subjectively valid, I call mere judgments of perception. … All of our judgments are at first mere judgments of perception: they are valid merely for us, i.e., for our subject, and only afterwards do we give them a new relation, namely to an object, and we intend that [the judgment] is supposed to be also valid for us at all times and precisely so for everyone else; for, if a judgment agrees with an object, then all judgments about the same object must also agree among one another, and thus the objective validity of the judgment of experience signifies nothing else but its necessary universal validity’.(Kant, 51)
It is evident that Kant thinks that the judgments addressing cause-effect dichotomy are intrinsically subjective, however, such subjectivity should be rightly interpreted. Kant utilizes the notion of subjectivity in a manner different from traditional definition. For Kant subjectivity of judgments is grounded in their use of a priori synthetic concepts of transcendental subject. The latter, does not imply that such notions lack universal logical importance, but instead that their logical coherence is guaranteed by the reason, which is the only source thereof.
Based on the latter interpretation, one should outline basic findings of Kant’s argument.
Kant uses Humean doubt as a starting point for his own analysis of rational categories of cognition. Kant pays tribute to Humean skepticism, because the latter opened possibilities for the development of critical philosophy. Humean critique of metaphysics coincides with Kant’s own project of Critique of the Pure Reason.
However, unlike Hume, Kant thinks that logical ties should not be searched in empirical experience. The latter only provides material, which is synthesized by transcendental a priori concepts.
Kant reasonably criticizes Hume for his conclusion that only habit should be regarded as the reason for causal ties. Kant shows that judgments are characterized by logical necessity. For instance, when we say that ‘Sun brings heat’, that means that it is necessary condition, which does not depend on experience and is based on certain law of necessity. In this way, Kant manages to overcome Humean doubt and build new philosophical edifice.