Which words serve to identify the characters defined by their wisdom, to describe them and their intellectual life? Without a doubt, it involves a great number of words that, once traced, classified, recorded and reorganized, offer various types of analyses. Here, the study has been restricted to five Spanish works of the 13th century: two born in a western setting – The "Libro de Alexandre" and the "Libro de Apolonio" – and three of an eastern origin – "Sendebar", "Calila e Dimna", "Barlaam y Josafat". From the numerical results and statistics obtained, we can observe how the corpus of words shared by the five works organizes itself, we can describe the most significant differences in the choice of the lexicon between western texts and eastern texts and we can examine the outstanding aspects of the vocabulary of each work separately. The texts will surprise the careful reader: the words are not always where we expect them to be.