Men are qualified for civil liberty in exact proportion to their disposition to put moral chains upon their own appetites
 Theodore Roosevelt, State of the Union Address. copy citation

Context

“but it is also the most difficult. We who possess this priceless boon, and who desire to hand it on to our children and our children's children, should ever bear in mind the thought so finely expressed by Burke: "Men are qualified for civil liberty in exact proportion to their disposition to put moral chains upon their own appetites; in proportion as they are disposed to listen to the counsels of the wise and good in preference to the flattery of knaves. Society cannot exist unless a controlling power upon will and appetite be placed somewhere, and the less of it there be within the more there must be without.” source