The paper aims to cast light on the kind of proof involved in central transcendental arguments. It is suggested that some of the difficulty associated with such arguments may result from the tendency to construe them simply as articulating relations between concepts or propositional contents. A different construal, connected with phenomenological description, is outlined, as a way of bringing out the force of these arguments. It is suggested that it can be fruitful to think in terms of this construal in understanding some of Kant's transcendental proofs. The recommended construal also helps to understand the nature of the link between transcendental arguments and transcendental idealism.