A hard path to walk that leads to any place and to no place

Immanuel Kant wrote:

Reason must in all its undertakings subject itself to criticism; should it limit freedom of criticism by any prohibition, it must harm itself, drawing upon itself a damaging suspicion. Nothing is so important through its usefulness, nothing so sacred, that it may be exempted from this searching examination, which knows no respect for persons. Reason depends upon this freedom for its very existence. For reason has no dictatorial authority; its verdict is always simply the agreement of free citizens, of whom each one must be permitted to express, without let or hindrance, his objections or even his veto [(Immanuel Kant, Critique of Pure Reason, A 738-9), emphasis added].