 This conception adopted by Pereira to explain the integral unity of the rational soul needed to be developed to explain the integral unity of the human being. Many of his statements, both in the Antoniana and in the Apologia, pointed out that the human being is not only the soul, but the conjunction of a body and a soul (see, for example, AM: I.687, I.697, II.1077, II.1149). In fact, he never abandoned the formal relationship that the rational soul has with regard to the body (see González Vila 1975: 41).  However, the concept of form used by Pereira permitted him to speak of a plurality of forms in a single subject (as many Averroists defended: see above). For him, the unity of a compound is not given by the uniqueness of a substantial form, but by the hierarchy of several forms under a superior one that gives the compound its ultimate denomination. In a human, who is the most complex being of creation, there would be a compound of compounds. Therefore, the rational soul is not the only substantial form in him, although it is the only human form since it crowns that hierarchy of forms and confers to the whole human being his nature and denomination. Pereira defended what can be considered a dynamic hylomorphism which was surely built on his own biological experience as a doctor. However, the body-soul union of which the Spanish physician spoke in his Antoniana can hardly be considered substantial sensu stricto, mainly because in his book there is no detailed explanation of the relation of the soul to the body, or of what kind of union there is between two natures so different in themselves. For him it is a factum that in human beings these two natures converge, but he failed to explain this question – probably for the sake of a coherence that was perhaps impossible.