Final answer:
Kant maintained that a priori knowledge can inform necessary truths but does not confirm their existence in reality. Categories of understanding innate to human cognition shape this a priori knowledge. The necessary truths we apprehend are thus not indicative of the world in itself, which remains unknowable.
Step-by-step explanation:
Immanuel Kant believed in the distinction between a priori and empirical knowledge. He held that a priori knowledge is independent of experience but that it does not always have to be reached through reason alone; it can also be informed by experience. Kant suggested that a priori truths are closely linked to necessary truths because they are not contingent upon sensory experience.
However, the necessity of a truth does not ascertain its ontological status in reality. Kant's famous critique of Anselm's ontological argument for the existence of God illustrates this: while we might necessarily conceive of a God, this does not confirm God's actual existence.
Moreover, Kant argued that humans will never know things-in-themselves. We are limited by our perceptual framework which shapes our experience, requiring categories of understanding that are innate and necessary for making sense of our intuitions. Thus, necessary truths, such as those found in mathematics, might actually be resultant of this innate structure of the human mind rather than some immutable truths about the world itself. The necessary truths are the products of the pure form of sensible intuition (space and time) and the categories of understanding.