[joeamroo]

Think of this: can you possibly learn all aspects of a subject strictly using A priori knowledge? How about knowledge that comes through serendipity? The Manhattan project had to gather the knowledge of multitudes of thinkers in order to workout (risking the eventual leak). I see no reason to think in private unless you’re thinking of strictly personal ideas (which might benefit from other people’s critiques) or if you’re a philosopher trying to prove that you can gain extensive knowledge strictly a priori (Hegel comes to mind)