This article underlines doctor Justo Arosemena profundity of his ethical thought. He was a jurist who cultivated different disciplines of thinking, apart form Law, an exceptional trait in the nineteenth century Panamanians. Therefore, he underlined, since his youth, the importance of the social and human sciences, qualified by him as the “moral and political sciences”. The author praises his critical thought, his rationalism, his pragmatic ethics, his liberty and equality conceptions, the defence of the legal State, what is right and wrong, the political morals, the popular elections,the diplomacy, the militarism, the role of education, the penal system, and the ethics in the light of different books and writings composed by the eminent poligrapher that confered to the ethics and morals an honorable place in his progresive philosophy