The volume was published in 1958, at a time when there was still debate about the legal significance of the Constitution and when labor was still regulated by corporatist norms. The work offers a systematic reinterpretation of labor law in light of constitutional principles. The relevance of the individual, the principle of substantive equality enshrined in Article 3(II) of the Constitution, and the right to work are at the foundation of recognizing a society divided by economic and social differences, which presupposes a rebalancing through a system of guarantees aimed at balancing entrepreneurial economic power with the social and political primacy of labor forces. It is in light of the fundamental principles of the Constitution that the rights to work, to adequate compensation, to social security, and to trade union freedom become non-negotiable rights of the individual, immediately effective even in relations between private parties. And it is always on the basis of principles of democracy and freedom that the rights of collective autonomy are defined in the essay. Despite the more than sixty years filled with history and changes that separate us from this first monograph by Carlo Smuraglia, the principles affirmed therein remain at the foundations of the current labor regulatory system and, at the same time, indicate a path towards the realization of constitutional principles that has never lost relevance.