There is no figure in the freedom of conscience domain that would match the breadth and the scope of Michael Servetus’s outlook and his importance to the evolution of this outstanding concept to understand the development of mankind in Western Europe. Servetus stands out for having left us two outstanding legacies: the right to free conscience and the freedom of speech, and the use of radicalism as intellectual method.

Recent historical studies reveal that the ideas of Servetus on tolerance marked a turning point in the intellectual discussion which led to the recognition of the freedom of thought and conscience as an inalienable human right. His example influenced the works of John Locke and, through him, the ideas of the statesmen who drafted the Constitution of the United States of America and its first Amendments. Servetus was also a radical thinker, devoted to the search truth above all the established dogmas, and without taking into account the consequences that this radicalism could have for his life.