Everything is up for investigation, however eventually one must draw conclusions, arrive at answers to ones questions. There used to be buttons with “ Question Authority.” Yes ! question any and everything, but eventually, while still with many years left in one’s life in which one acts on one’s ideas , one must reach answers about which one has enough certainty to act on those answers;test one’s answers in practice; the proof of the pudding is in the eating . Trial and error . Trial is practice in objective reality, objective cultural and natural reality .