Abstract
In this paper I analyze the difficult question of the truth of mature
scientific theories by tackling the problem of the truth of laws. After introducing
the main philosophical positions in the field of scientific realism, I discuss and
then counter the two main arguments against realism, namely the pessimistic metainduction
and the abstract and idealized character of scientific laws. I conclude by
defending the view that well-confirmed physical theories are true only relatively to
certain values of the variables that appear in the laws