The attitudes and beliefs of teachers and future physics teachers about epistemological aspects of Physics play a very important role in teaching the discipline. In this paper, after describing some of the most important results reported in the literature, we present the main results of the implementation of the CLASS test on attitudes and beliefs to hundreds of student and physics teacher in Uruguay. The results corresponding to the teaching students are similar to those who choose careers with an emphasis on Physics and Mathematics and, in turn, are clearly below those presented by professors and researchers. We highlight then the need to make explicit the issues related to epistemological attitudes and beliefs in our classes.