Immanuel Kant (22 April 1724 – 12 February 1804) was an influential Prussian German philosopher in the Age of Enlightenment.
In his doctrine of transcendental idealism, he argued that space, time, and causation are mere sensibilities; "things-in-themselves" exist, but their nature is unknowable.In his view, the mind shapes and structures experience, with all human experience sharing certain structural features.
He drew a parallel to the Copernican revolution in his proposition that worldly objects can be intuited a priori ('beforehand'), and that intuition is therefore independent from objective reality.
Kant believed that reason is the source of morality, and that aesthetics arise from a faculty of disinterested judgment. Kant's views continue to have a major influence on contemporary philosophy, especially the fields of epistemology, ethics, political theory, and post-modern aesthetics. (4)
Inner sense is, according to Kant, the means by which we are aware of alterations in our own state. Hence all moods, feelings, and sensations, including such basic alterations as pleasure and pain, are the proper subject matter of inner sense.
Self Consciousnesss - First, he treats inner sense: When we know ourselves as the object of a representation in inner sense, we “know even ourselves only .. as appearance …” (A278).
Inner sense … represents to consciousness even our own selves only as we appear to ourselves, not as we are in ourselves. For we intuit ourselves only as we are inwardly affected [by ourselves] (B153)? (1)
This transcendental designation, i.e., referring to oneself using ‘I’ without ‘noting any quality’ in oneself, has some unusual features. One can refer to oneself in a variety of ways, of course: as the person in the mirror, as the person born on such and such a date in such and such a place, as the first person to do X, and so on, but one way of referring to oneself is special: it does not require identifying or indeed any ascription to oneself. So Kant tells us... Transcendental apperception is the uniting and building of coherent consciousness out of different elementary inner experiences (differing in both time and topic, but all belonging to self-consciousness). (1) Prior syntheses are made possible by the categories. Categories allow us to synthesize the self and the objects. (3)
To begin with, Kant's distinction between the a posteriori being contingent and particular knowledge, and the a priori being universal and necessary knowledge, must be kept in mind. If we merely connect two intuitions together in a perceiving subject, the knowledge is always subjective because it is derived a posteriori, when what is desired is for the knowledge to be objective, that is, for the two intuitions to refer to the object and hold good of it for anyone at any time, not just the perceiving subject in its current condition. What else is equivalent to objective knowledge besides the a priori, (universal and necessary knowledge)? Before knowledge can be objective, it must be incorporated under an a priori category of understanding.
For example, if a subject says, "The sun shines on the stone; the stone grows warm," all he perceives are phenomena. His judgment is contingent and holds no necessity. But if he says, "The sunshine causes the stone to warm," he subsumes the perception under the category of causality, which is not found in the perception, and necessarily synthesizes the concept sunshine with the concept heat, producing a necessarily universally true judgment.
To explain the categories in more detail, they are the preconditions of the construction of objects in the mind. Indeed, to even think of the sun and stone presupposes the category of subsistence, that is, substance. For the categories synthesize the random data of the sensory manifold into intelligible objects. This means that the categories are also the most abstract things one can say of any object whatsoever, and hence one can have an a priori cognition of the totality of all objects of experience if one can list all of them. To do so, Kant formulates another transcendental deduction.
Judgments are, for Kant, the preconditions of any thought. Man thinks via judgments, so all possible judgments must be listed and the perceptions connected within them put aside, so as to make it possible to examine the moments when the understanding is engaged in constructing judgments. For the categories are equivalent to these moments, in that they are concepts of intuitions in general, so far as they are determined by these moments universally and necessarily. Thus by listing all the moments, one can deduce from them all of the categories. (Compare this to Titchner's theory of introspective psychology).
One may now ask: How many possible judgments are there? Kant believed that all the possible propositions within Aristotle's syllogistic logic are equivalent to all possible judgments, and that all the logical operators within the propositions are equivalent to the moments of the understanding within judgments. Thus he listed Aristotle's system in four groups of three: quantity (universal, particular, singular), quality (affirmative, negative, infinite), relation (categorical, hypothetical, disjunctive) and modality (problematic, assertoric, apodeictic). The parallelism with Kant's categories is obvious: quantity (unity, plurality, totality), quality (reality, negation, limitation), relation (substance, cause, community) and modality (possibility, existence, necessity).
The fundamental building blocks of experience, i.e. objective knowledge, are now in place. First there is the sensibility, which supplies the mind with intuitions, and then there is the understanding, which produces judgments of these intuitions and can subsume them under categories. These categories lift the intuitions up out of the subject's current state of consciousness and place them within consciousness in general, producing universally necessary knowledge. For the categories are innate in any rational being, so any intuition thought within a category in one mind is necessarily subsumed and understood identically in any mind. In other words, we filter what we see and hear. (4)
In psychology we investigate ourselves according to our perceptions of the inner sense; but in logic we make the investigation on the grounds of what the intellectual consciousness supplies us with. Here the self appears to us as twofold (which would be contradictory): (1) the self, as the subject of thinking (in logic), which means pure apperception (the merely reflecting self) of which nothing more can be said, except that it is entirely simple perception. (2) The self, as the object of the perception, consequently also part of the inner sense, contains a multiplicity of definitions which make inner experience possible. To ask whether or not a man conscious of different inner mental changes (either of his thoughts or of fundamental principles assumed by him) can say that he is the selfsame man, is an absurd question. For he can be conscious of these changes in the first place only on condition that he represents himself, in the different situations, as one and the same subject. The human ego is indeed twofold as regards its form (manner of representation), but not with respect to its matter (content).’ (Anthropology from a Pragmatic Point of View, footnote to p.18). (2)
1. https://plato.stanford.edu/entries/kant-transcendental/#AppUni
2. http://www.generation-online.org/p/fpkantcogito.htm
3. https://en.wikipedia.org/wiki/Transcendental_apperception
4.
https://en.wikipedia.org/wiki/Immanuel_Kant#Categories_of_the_Faculty_of_Understanding