The term 'To Be, To Voltaire' is a reference to the famous French philosopher and writer, Voltaire. The crossword solutions for this term are 'ETRE, ' which is the French verb meaning 'to be.' This phrase is a play on words, as it references both Voltaire's famous quote 'I disapprove of what you say, but I will defend to the death your right to say it, ' as well as the philosophical concept of being.