The term ‘transcendental subject’ comes from Kant. Andy Blunden has this to say on the matter:
[1.] From the very start of the Critique of Pure Reason, Kant utilises the concept of ‘subject’, initially in the logical form owed to Aristotle, as the bearer of predicates, and then in the Cartesian sense, as a cogito, as when he asks:
“how can an external intuition anterior to objects themselves … exist in the human mind? Obviously not otherwise than in so far as it has its seat in the subject only, as the formal capacity of the subject’s being affected by objects.” [Critique of Pure Reason, p. 27]
[2.] Thus Kant maintains Descartes’ conception of the knowing subject, the cogito, and agrees that its existence, though only its existence, can be deduced from experience, as a necessary precondition for thinking. Kant also agrees that all conceptions and qualities ascribed to objects actually inhere in the subject itself.
[3.] Kant does not however draw what could be called “metaphysical” conclusions from the fact of existence of the cogito, that is, the subject in “I think.” He says that:
‘By this “I,” or “He,” or “It,” who or which thinks, nothing more is represented than a transcendental subject of thought = x, which is cognized only by means of the thoughts that are its predicates.’ [Critique of Pure Reason, p. 142]
[4.] What Kant means by “transcendental” can be explained thus.
The Empiricists had held that all knowledge enters the mind via sensation, and that knowledge was a result of the impact of bodies on the sense organs. Knowledge was therefore limited to the data of sensation and ideas built upon that data. As Berkeley and Hume had pointed out, this meant that the subject could have no real and reliable knowledge of anything ‘beyond sensation’. This conclusion flew in the face of common sense and rendered impossible the very idea of scientific knowledge of an objective world beyond the consciousness of the subject itself. On the other side was the dogmatism of uncritical claims to knowledge of the material world in itself, which ascribed no role whatsoever to the subject in interpreting the data of experience and constructing speculative systems and structures deemed to exist in the world itself, prior to and beyond experience. Resolution of this dispute was the principal stimulus for Kant’s work.
[5.] The opening words of the Critique of Pure Reason state that “all our knowledge begins with experience.” So this much Kant granted to the Empiricists. But it was self-evident that in fact people were able to make sense of the world, and that in thinking, we were evidently bringing to bear on the data of experience, conceptions which did not and could not originate in experience, because nothing corresponding to them existed or could exist in the outside material world.
[6.] In fact it turns out that:
‘[C]ertain of our cognitions rise completely above the sphere of all possible experience, and by means of conceptions, to which there exists in the whole extent of experience no corresponding object, seem to extend the range of our judgements beyond its bounds. And just in this transcendental or supersensible sphere, where experience affords us neither instruction nor guidance, lie the investigations of reason, which, on account of their importance, we consider far preferable to, and as having a far more elevated aim than, all that the understanding can achieve within the sphere of sensuous phenomena.’ [Critique of Pure Reason, p. 17]
[7.] So it is this “transcendental subject” which Kant aims to bring to light. And such a “transcendental subject” can only have transcendental predicates, that is to say, all we can say about it concern the limits and conditions of validity of knowledge of the most universal kind. Nothing of an empirical nature can be predicated of it.
It is quite worth reading the whole article with some attention. There is more on the transcendental subject in Kant at Beyond Appearances, at Esalen, of all places, and also in David Carr’s The Paradox of Subjectivity: The Self in the Transcendental Tradition (New York: Oxford University Press, 1999). This book has been reviewed in JHP and is available from Amazon.
In graduate school I was, of course, told by poststructuralists and various types of materialists that the transcendental subject was a bad thing. It existed in the noumenal and not the material world, and it was a “colonizing” subject – the Subject, in fact, of colonization. This has always seemed to me to be a gross oversimplification of the matter, and I believe Carr’s book may be an excellent corrective to this orthodoxy. Consider these reviews and book description, from Amazon:
“…a timely and refreshing defense of the tradition of transcendental philosophy in Kant and Husserl against Heidegger’s influential attack….The erudition and clarity of this fine study make it accessible to both undergraduate and graduate audiences. This is a welcome addition to all .” —Choice
“A brilliant and challenging defense of the legitimacy and distinctiveness of the transcendental tradition in modern philosophy takes the world as given and explores it factually…this is a splendid book, to be enjoyed by anyone interested in Kant, or in the philosophical problems that gripped him.” —The Philosophical Review
Much effort in recent philosophy has been devoted to attacking the metaphysics of the subject. Identified largely with French post-structuralist thought, yet stemming primarily from the influential work of the later Heidegger, this attack has taken the form of a sweeping denunciation of the whole tradition of modern philosophy from Descartes through Nietzsche, Husserl, and Existentialism. In this timely study, David Carr contends that this discussion has overlooked and eventually lost sight of the distinction between modern metaphysics and the tradition of transcendental philosophy inaugurated by Kant and continued by Husserl into the twentieth century.
Carr maintains that the transcendental tradition, often misinterpreted as a mere alternative version of the metaphysics of the subject, is in fact itself directed against such a metaphysics. Challenging prevailing views of the development of modern philosophy, Carr proposes a reinterpretation of the transcendental tradition and counters Heidegger’s influential readings of Kant and Husserl. He defends their subtle and complex transcendental investigations of the self and the life of subjectivity. In Carr’s interpretation, far from joining the project of metaphysical foundationalism, transcendental philosophy offers epistemological critique and phenomenological description. Its aim is not metaphysical conclusions but rather an appreciation for the rich and sometimes contradictory character of experience. The transcendental approach to the self is skillfully summed up by Husserl as “the paradox of human subjectivity: being a subject for the world and at the same time being an object in the world.”
Proposing striking new readings of Kant and Husserl and reviving a sound awareness of the transcendental tradition, Carr’s distinctive historical and systematic position will interest a wide range of readers and provoke discussion among philosophers of metaphysics, epistemology, and the history of philosophy.