This paper explains the political thought of Alfonso Fernández de Madrigal, known as "El Tostado", in his De optima politia. This little work offers some reflections on the political community, on the city considered as centre of civic and political activity, and on the best possible forms of government, as well as criticism of some platonic elements such as the communism of wives, and the position and value of the family. He introduces Aristotle as his source and principal philosophical inspiration in pre-humanist Spain, and in the academic environment of the first half of the 15th century. [ABSTRACT FROM AUTHOR]