I've always thought of philosophy - good philosophy, at least - as being both academic and practical. I have to wonder about some of the great minds who have undertaken various philosophical exercises. When Kant was "scandalized" by Hume's writings, were his (Kant's) reactions based upon something he really believed?
I don't mean to call into question Kant's sincerity, and hopefully my intentions will become clear by the end of this post. Take, for example, Kant's insistence that causation is a mental construct, which is part of the phenomenal realm. Would Kant have really thought that causation has nothing whatsoever to do with the realm of the noumena? Or, as I suspect, did he set out to demonstrate as much as he thought possible and simply leave his belief in causation-qua-noumena as a rationally-held belief that couldn't have absolute metaphysical certitude?
We find traces of a less-than-skeptical Hume, as well. Not even he questioned the truth of ex nihilo nihil fit. He only questioned our ability to prove it with Cartesian certitude.