The opportunities offered by the universities natural lawly reinforced the old tendency of scholars to become teachers. And since the public was then as prone as it is now to overemphasize the teaching at the expense of the production of what is being taught, medieval men of science were and are usually referred to as Schoolmen or Scholastics (doctores scholastici). In order to disabuse himself of prevailing preconceptions, the reader had better see in these scholastic doctors simply college or university professors. St. Thomas, then, was a professor. His Summa Theologica was, as he informs us in the preface, conceived as a textbook for beginners (incipientes).