Desiderius Erasmus considered that the education of children has to start at an early age. To get a better understanding of Erasmus’ theories about the education, this paper analyses the use of his term eruditio, but also the use of terms such as ratio, usus and philosophia. The aim is to point out the interesting link between the contemporary understanding of critical thinking and Erasmus’ concept of eruditio. Furthermore, for a better understanding of his perception of education (but also of the connection of his theory with contemporary theories of critical thinking), we analyse Erasmus’ description of characteristics of a good teacher. Here mentioned description of a good teacher, in some aspects, link Erasmus with contemporary theorists (and practitioners) such as John Dewey and Oscar Brenifier. As early training and practice for the development of a proper inference, Erasmus suggests fables, language exercises and proverbs, which is similar to what contemporary theorists and practitioners of critical thinking and philosophy with children do.