 About his own vision of empirical method and scientific research, the Prologues of his books provide us with enlightening information. In his Novae veraeque medicinae Pereira proclaims that the duty of a scientist is to use the instruments of logic and experience to reach the truth, without becoming entangled in the subtleties of language and sterile sophistry. In this sense, Pereira denounces Erasmus and his followers for having wasted the intelligence of many young people who could have devoted themselves to science (NVM: 1a). Also, at the beginning of the Antoniana Pereira rejects the principle of authority if it is used to replace rational demonstration. Against those who base their doctrines in Aristotle, Pereira says: 