The phrase 'master of theory' is correct and usable in written English.
You can use this phrase to describe someone who is particularly knowledgeable in a specific theoretical field. For example, "He is a master of theory, with an impressive understanding of the history of philosophy."
In came Tesla--a master balancer of theory and experiment.
The game features finches, which were a favorite subject of that master of the theory of evolution himself, Charles Darwin.
Kato was a long established master of operator theory.
A master of queer theory.
Lest we think that queues are somehow more prevalent among the revolutionary French, the quaint British or the mild-mannered Canadians, we should remember Disneyland, the master of queuing-theory-put-into-practice when it comes to getting families with restless children to repeatedly stand in 40-minute lines for two-minute rides.
Signac painted until his death in 1935 at age 72, renowned as a master of the theories of color and light.
The various financial regulators, sub-regulators and masters of political theory – the Treasury, the Bank of England, the Financial Conduct Authority (FCA) and others – have not seen to it that British consumers or small businesses have more access to finance and, conversely, a more creative market for their savings.
It is no surprise that, by feverishly indulging conspiracy theories of many kinds, Donald Trump would end up reintroducing America to the master conspiracy theory of them all, the first of the modern kind, and still the biggest and strangest: the one surrounding the assassination of J.F.K.
Peter Frumkin, a sociologist at the Lyndon B. Johnson School of Public Affairs at the University of Texas, says donors operate from either of two "master theories of giving".
