Self Questioning Quotes by Robert M. Pirsig, Arthur Schopenhauer, Tony Judt, Sylvia Plath, Carl Sagan and many others.

The truth knocks on the door and you say, go away, I’m looking for the truth, and it goes away. Puzzling.
All truth passes through three stages. First, it is ridiculed. Second, it is violently opposed. Third, it is accepted as being self-evident.
Judaism for me is a sensibility of collective self-questioning and uncomfortable truth-telling. I feel a debt of responsibility to this past. It is why I am Jewish.
Life has been some combination of fairy-tale coincidence and joie de vivre and shocks of beauty together with some hurtful self-questioning.
Indeed the reasoned criticism of a prevailing belief is a service to the proponents of that belief; if they are incapable of defending it, they are well advised to abandon it. This self-questioning and error-correcting aspect of the scientific method is its most striking property.