Our repeated failure to fully act as we would wish must not discourage us. It is the sincere intention that is the essential thing, and this will in time release us from the bondage of habits which at present seem almost insuperable.
— Thomas Troward

The diversity in the faculties of men, from which the rights of property originate, is not less an insuperable obstacle to an uniformity of interests. The protection of these faculties is the first object of government.
James Madison insuperable quote

The popularity of disaster movies expresses a collective perception of a world threatened by irresistible and unforeseen forces which nevertheless are thwarted at the last moment. Their thinly veiled symbolic meaning might be translated thus: We are innocent of wrongdoing. We are attacked by unforeseeable forces come to harm us. We are, thus, innocent even of negligence. Though those forces are insuperable, chance will come to our aid and we shall emerge victorious.
— David Mamet

Conceit is an insuperable obstacle to all progress.
— Ellen Terry

There are no insuperable constitutional difficulties.
— insuperable quotation by Lionel K. Murphy