The comparative method taught in this book allows us to compare solutions from different countries and legal systems and to use them as source of inspiration when looking for solutions to legal problems. In the legislative process, a purely domestic perspective has long been considered outdated. In fact, national and international legislatures have always relied on, and benefited from, significant comparative research during the drafting stage of private law legislation. When interpreting domestic law, courts in a certain number of jurisdictions also draw inspiration from foreign solutions and increasingly from “common principles” of law derived from comparison. In other jurisdictions, it is still less common for the judge to take inspiration from the comparative approach when deciding cases according to their domestic law.