in theory
• used in describing what is supposed to happen or be possible, usually with the implication that it does not in fact happen.
• "in theory, things can only get better; in practice, they may well become a lot worse"
Similar:
in principle,
on paper,
in the abstract,
all things being equal,
in an ideal world,
hypothetically,
en principe,
Opposite:
in practice,
in reality,
