Fools rush in where incumbents fear to tread.
Do things that incumbents can't or won't do because it's economically or technically infeasible.
With each door one women walks through it is incumbent to bring another woman through it with her.
I think we are incumbent, I am incumbent, the Who is incumbent, anybody that produces anything by me is incumbent by my Englishness.
Where there is no hope, it is incumbent on us to invent it.