How do you know what you claim to know?
Transcendental deduction is a philosophical concept developed by Immanuel Kant in his classic work "The Critique of Pure Reason," which was first published in German in 1781 with a second edition published in 1787. This classic work is often cited as one of the most influential works in the history of philosophical thought. The concept of transcendental deduction is important because it forms an epistemological category that helps to explain how knowledge can be derived without reliance upon experience or sense data. Epistemology, simply put, is the philosophical inquiry into how it is that humans can know anything.
Definition
Transcendental deduction is the explanation of the manner in which concepts can relate a priori to objects. A priori ("from the former") is knowledge that is independent of experience and the senses. Kant argued that all knowledge begins with experience; however, all knowledge does not arise out of experience. For instance, a person sees an object in the sky and immediately, without thinking or trying to gain further insight into the object, concludes that the object is a flying saucer. This conclusion is transcendental in that the concept of flying saucer is beyond the experience and the senses even though the person experiences an object in the sky. It is a deduction in that the person moves from the universe of objects in the sky (airplanes, birds, balloons, for example) to the specific concept of flying saucer, even though he may have never before encountered a flying saucer.
Kant's Example
In expounding on the concept of transcendental deduction, Kant stated, "Mathematics is an example of how far, independently of experience, we can progress in a priori knowledge." A person can know that one plus one equals two without having to experience the combining of two objects or having to sense such a combination. In fact, mathematics involves a whole system of facts and figures that most people will never experience but which such people can know. Further, even when a person goes to the grocery store and gives the cashier a $20 bill to pay a $19.95 amount, the customer knows to expect 5 cents in change even though the customer may not have experienced this particular situation before. The math of the transaction is transcendent of the experience. The knowledge comes not from the experience but from knowing mathematics.
Significance
Prior to Kant, empiricism was the rule of the day in epistemology. A person could know only through experience and the senses. In theology, however, revelation and faith were prominent epistemological categories, but these did not carry over into philosophy. Interestingly, Kant's concept of transcendental knowledge would lay the foundation for the Transcendentalist movement in New England with such prominent adherents as Ralph Waldo Emerson and Henry David Thoreau. In that movement, the sources of transcendental knowledge are the "oversoul" and "nature," respectively. These later developments were not necessarily deviations from Kant's work because Kant did not spend much print arguing the source of transcendental knowledge; he merely stated it was a deep sense of intuition and left it to those who came after him to further develop that source.
Theories/Speculation
The biggest criticism of Kant's epistemological category has come from theologians who argue that Kant ignored the value of revelation from God and the continuing presence of the indwelling of the Holy Spirit that "teaches" humans all sorts of things. Some philosophers complain that Kant ignored the innate knowledge humans have from God, as Plato and Aristotle both argued. And although he is oftentimes credited with infusing God-talk into psychoanalysis, Carl Jung's category of the "collected unconscious" seems to run counter to Kant's intuition, at least on the surface.
Conclusion
Notwithstanding the previous criticisms, a resurgence of interest in Kant has occurred among scholars and students alike since Peter Strawson published his essay, "The Bounds of Sense: An Essay on Kant's Critique of Pure Reason," in 1990. As for theologians, many of them, especially those with a view of a transcendent God, have begun to read Kant's transcendental deduction as an appeal to God knowledge since God is transcendent of human experiences and senses.
