While it is not always profitable to analogize "fact" to "fiction," La Fontaine's fable of the crow, the cheese, and the fox demonstrates that there is a substantial difference between holding a piece of cheese in the beak and putting it in the stomach. Felix Frankfurter
You think slavery is right and should be extended; while we think slavery is wrong and ought to be restricted. That I suppose is the rub. It certainly is the only substantial difference between us. Abraham Lincoln
If there is a substantial difference between a gay couple and a childless heterosexual couple, I'm unable to see it. Daniel Keys Moran
The only substantial difference between them, and the one that divided them politically almost since birth, was their system of labor. William C. Davis (historian)