Abstract
According to some part of the procedural legal scholarship, Brazilian due process of law
incorporates principles and values that reflect the notion of “fair trial”. This expression operates as a legal
ground for determining the interpretation and application of courts decisions. However, the concept
“justice” that characterizes procedural law is a shared concept between law and morality, so that issues
about moral concepts become central issues to procedural law. Thus this sharing brings procedural law
closer to metaethics, the discipline whose object are concepts and ethical actions. As a discipline that
copes with second-order questions, metaethics makes it possible to identify at least three challenges to the
notion of fair trial: metaphysical, epistemological, and semantic. To this day none of the three challenges
has been adequately addressed.
