Baruch Spinoza, a descendant of Portuguese Jews, is one of the greatest minds in European philosophical tradition. His life was marked by double excommunication – Spinoza was first excommunicated by Holland’s Christian majority and afterwards by Amsterdam’s Jewish community. In both cases, the reasons were of a religious nature. In the 17th century, it was not easy to be a member of the Jewish minority in Christian Europe, but it was even more dangerous to abnegate the theistic basis of Jewish religion. But Spinoza was committed to intellectual freedom so strongly that he sacrificed his social background. During his lifetime, he published only The principles of Descartes’s philosophy and the unsigned Theological – Political Treatise. Because of his subversive standpoints, Spinoza was investigated by the Inquisition. Soon after publishing, all of his books were put on the Index Librorum Prohibitorum, a list of banned works. The modest thinker became famous for his posthumously published masterpiece entitled Ethics, in which he unfolded his own principles of ontology, epistemology and ethics. Although Spinoza followed the influences of Stoicism, rationalism and pantheism, his style and thought were mostly unique. It is absolutely impossible to present the wisdom of Ethics in a few sentences, because it is grounded on a complex ontology including omnipresent substance represented through two main modes, namely the physical and the psychical. Spinoza’s rationalism is not dogmatic, because the main maxim of his ethics – amor Dei intellectualis, intellectual love of the divine – transcends the borders of reason and reaches into the field of faith. But according to Spinoza, only reason can undermine the superstitions which claim that there is absolute evil and absolute good. The correlation between good and evil can be understood through Spinoza’s rational principle omnis determinatio is negatio, every determination is negation, which shows that there is no good without evil and no being without nought.