We cannot teach citizenship if we are not citizens; we cannot free others if we have forgotten the appetite of freedom.
 G. K. Chesterton, What's Wrong with the World (1910). copy citation

Context

“called dullards if they still adhere to conventions, and called loafers if they still love liberty. Now I am concerned, first and last, to maintain that unless you can save the fathers, you cannot save the children; that at present we cannot save others, for we cannot save ourselves. We cannot teach citizenship if we are not citizens; we cannot free others if we have forgotten the appetite of freedom. Education is only truth in a state of transmission; and how can we pass on truth if it has never come into our hand? Thus we find that education is of all the cases the clearest for our general purpose.” source