Because life just isn’t long enough

"All this is true. But what follows from it? What cannot follow is that we have to assume all alternative viewpoints are equally valid until we have thoroughly examined them for ourselves and proved otherwise. This is a policy we cannot follow. They are just too many belief systems in the world, too many explanations offered as to why we are here and how we ought to live. How would one set about trying to examine the truth of all of them from within, refusing to be satisfied with what to insiders would seem a superficial understanding? It can’t be done because life just isn’t long enough. Some of these alternatives actually demand a lifetime of practice, which means you could ‘try out’ no more than one anyway."