by Scott F. Aikin and Robert B. Talisse
Consider the nihilist who provides us with an argument with the conclusion that nothing exists, or that there are no norms for reason. Take the relativist who contends that all facts are relative to some perspective. Note the skeptic who consistently criticizes not only our claims to knowledge, but our very standards. Call such views Transcendental Pessimism. An appealing and longstanding reply to Transcendental Pessimism is that it is self-defeating in some way. The nihilist nevertheless avows a fact and relies on norms of rationality to run the argument for his own conclusion. The relativist isn't just saying that it's all relative to her perspective, but that it's all relative full stop. The skeptic's conclusion that we have no knowledge or have no reliable means to assess knowledge purports to be a knowledge-like commitment held on purportedly good epistemic grounds. The critical line is this: Transcendental Pessimist views cannot be consistently thought. Such views, to make sense at all, must presuppose precisely what they deny.
So far, this self-defeat maneuver against nihilists, relativists, and skeptics is but an inarticulate hunch. Transcendental arguments are attempts at making that hunch explicit, not only about how the negative views are self-defeating, but also regarding the positive views worth preserving. That is, we deploy transcendental argumentation not only as a critical line against Transcendental Pessimism, but we also (and perhaps thereby) establish some positive conclusion. Call this objective Transcendental Optimism.
Immanuel Kant is widely acknowledged to be the first to overtly use the argument type. The primary example of Kantian transcendental argument comes in the Second Analogy of Kant's Critique of Pure Reason. The rough form of argument runs as follows: One can judge a series of representations is evidence of a series of events only if one holds that the series is asymmetric (it must happen in that order, not in a reverse or other order). One can believe that the representations are asymmetric only if one holds that the events represented are similarly asymmetric. If a series of states is asymmetric, the earlier states are causes of the later states. Therefore: One can take a series of representations as evidence only if one takes them as evidence of a causal order. Experience can be a source of information only if there is a causal order.