Transcendental idealism
Transcendental idealism is a philosophical system[1] founded by German philosopher Immanuel Kant in the 18th century. Kant's epistemological program[2] is found throughout his Critique of Pure Reason (1781). By transcendental (a term that deserves special clarification[3]) Kant means that his philosophical approach to knowledge transcends mere consideration of sensory evidence and requires an understanding of the mind's innate modes of processing that sensory evidence.[4]
In the "Transcendental Aesthetic" section of the Critique of Pure Reason, Kant outlines how space and time are pure forms of human intuition contributed by our own faculty of sensibility. Space and time do not have an existence "outside" of us, but are the "subjective" forms of our sensibility and hence the necessary a priori conditions under which the objects we encounter in our experience can appear to us at all. Kant describes time and space not only as "empirically real" but transcendentally ideal.[5]
Kant argues that the conscious subject recognizes the objects of experience not as they are in themselves, but only the way they appear to us under the conditions of our sensibility. This fits his model of perception outlined at the outset of the "Transcendental Aesthetic" by which he distinguishes the empirical reality of appearances studied by the empirical sciences from the noumenal reality of things as they are in themselves, independent of empirical observation.[6] Thus Kant's doctrine restricts the scope of our cognition to appearances given to our sensibility and denies that we can possess cognition of things as they are in themselves, i.e. things as they are independently of how we experience them through our cognitive faculties.[7]
Background[edit]
Although it influenced the course of subsequent German philosophy dramatically, exactly how to interpret this concept was a subject of some debate among 20th century philosophers. Kant first describes it in his Critique of Pure Reason, and distinguished his view from contemporary views of realism and idealism, it remains the case that philosophers do not agree on how sharply Kant differs from each of these positions.
Transcendental idealism is associated, if not identified, with the formalistic idealism Kant discusses in his Prolegomena to any Future Metaphysics, although recent research has tended to dispute this identification. Transcendental idealism was also adopted as a label by the subsequent German philosophers Johann Gottlieb Fichte and Friedrich Wilhelm Joseph von Schelling, Arthur Schopenhauer, and in the early 20th century by Edmund Husserl in the novel form of transcendental-phenomenological idealism.
P. F. Strawson[edit]
In The Bounds of Sense, P. F. Strawson suggests a reading of Kant's first Critique that, once accepted, forces rejection of most of the original arguments, including transcendental idealism. Strawson contends that, had Kant followed out the implications of all that he said, he would have seen that there were many self-contradictions implicit in the whole.[12]: 403
Strawson views the analytic argument of the transcendental deduction as the most valuable idea in the text, and regards transcendental idealism as an unavoidable error in Kant's greatly productive system. In Strawson's traditional reading (also favored in the work of Paul Guyer and Rae Langton), the Kantian term phenomena (literally, things that can be seen—from Greek: phainomenon, "observable") refers to the world of appearances, or the world of "things" sensed.[13]: 99–101 They are tagged as "phenomena" to remind the reader that humans confuse these derivative appearances with whatever may be the forever unavailable "things in themselves" behind our perceptions. The necessary preconditions of experience, the components that humans bring to their apprehending of the world, the forms of perception such as space and time, are what make a priori judgments possible, but all of this process of comprehending what lies fundamental to human experience fails to bring anyone beyond the inherent limits of human sensibility. Kant's system requires the existence of noumena to prevent a rejection of external reality altogether, and it is this concept (senseless objects of which we can have no real understanding) to which Strawson objects in his book.
Henry E. Allison[edit]
In Kant's Transcendental Idealism, Henry E. Allison proposes a new reading that opposes, and provides a meaningful alternative to, Strawson's interpretation.[14] Allison argues that Strawson and others misrepresent Kant by emphasising what has become known as the two-worlds reading (a view developed by Paul Guyer). This—according to Allison, false—reading of Kant's phenomena/noumena distinction suggests that phenomena and noumena are ontologically distinct from each other. It concludes on that basis that we somehow fall short of knowing the noumena due to the nature of the very means by which we comprehend them. On such a reading, Kant would himself commit the very fallacies he attributes to the transcendental realists. On Allison's reading, Kant's view is better characterized as a two-aspect theory, where noumena and phenomena refer to complementary ways of considering an object. It is the dialectic character of knowing, rather than epistemological insufficiency, that Kant wanted most to assert.
Allison's two-aspect interpretation also serves as an at least partially successful defense of transcendental idealism, particularly within anglophone analytic philosophy. Although his interpretive position is contested among Kant scholars, including Anja Jauernig in her 2021 monograph The World According to Kant,[15] Allison's Kant's Transcendental Idealism uncontroversially helped start the late-20th century revival of contemporary interest in Kant's metaphysical, or as Allison describes it 'metaepistemological', transcendental idealism.[16]
Opposing views: Naïve realism[edit]
Opposing Kantian transcendental idealism is the doctrine of naïve realism, that is, the proposition that the world is knowable as it really is, without any consideration of the knower's manner of knowing. This has been propounded by philosophers such as Hilary Putnam,[17] John Searle,[18] and Henry Babcock Veatch. Naïve or direct realism claims, contrary to transcendental idealism, that perceived objects exist in the way that they appear, in and of themselves, independent of a knowing spectator's mind. Kant referred to this view as "transcendental realism," which he defined as purporting the existence of objects in space and time independent from our sensibility.[19]