During the Indian Constitutional Debates, B.R. Ambedkar said something like this (this source contains obvious typos)
Libertarians focus only on liberty. The last clause is also often overlooked. The fact is that there can be the rule of law only if most people voluntarily follow the law. (As the experience of the Prohibition in the US showed, there is no police force, no justice system that keep a law which a large number of people don't want to follow.)
The third thing we must do is not to be content with mere political democracy. We must make our political democracy a social democracy as well. Political democracy cannot last unless there lies at the base of it social democracy. What does social democracy mean? It means a way of life which recognises liberty, equality and fraternity as the principles of life. These principles of liberty, equality and fraternity are not to be treated as separate items in a trinity. They form a union of trinity in the sense that to divorce one from the other is to defeat the very purpose of democracy. Liberty cannot be divorced from equality; equality cannot be divorced from liberty. Nor can liberty and equality be divorced from fraternity. Without equality, liberty would produce the supremacy of the few over the many. Equality without liberty would kill individual initiative. Without fraternity, liberty and equality could not become a natural course of things. It would require a constable to enforce them.