theoretical science

theoretical physics

That shows his theoretical background.

The Greeks made theoretical models of geometry.

he worked the problem out theoretically

the Church was...theoretically inerrant and omnicompetent-G.G.Coulton

the lack of consensus reflected differences in theoretical positions

Renewable energy such as solar energy is theoretically inexhaustible.

As for the theoretical side, Peterson's claim is pertinent to our discussion.

This meeting is a waste of time. Everybody is just talking in vague theoretical terms.