From the following definition, it seems that the uncertainty principle is an epistemological statement. "Heisenberg's uncertainty principle, is any of a variety of mathematical inequalities asserting a fundamental limit to the precision with which certain pairs of physical properties of a particle, known as complementary variables, such as position x and momentum p, can be known." That is, we cannot know the position and momentum of a particle to infinite precision. But nothing is said about the ontology of the particle. So a particle could have a precise position ##x=0## and a precise momentum ##p=0## as long as the value of both variables cannot be known to us simultaneously. But the following exercise seems to suggest that the uncertainty principle is an ontological statement, that is, a particle cannot have a precise position and a precise momentum simultaneously. So is the uncertainty principle an epistemological statement or an ontological one?