Noun
One who forms theories; one given to theory and speculation; a speculatist.
Source: Webster's dictionaryA theorist today is hardly considered respectable if he or she has not introduced at least one new particle for which there is no experimental evidence. Steven Weinberg
I'm not a conspiracy theorist - I'm a conspiracy analyst. Gore Vidal
The Florentines, who were incapable of ruling themselves, produced a great theorist of government: Machiavelli. The Venetians had no theorists and evolved a model Republic. Mary McCarthy
He was lucky enough to rub shoulders with a fellow student, Mr. W T. Newlyn, now lecturing on money at the University of Leeds, who was less of an engineer but more of a monetary theorist than himself. Together they discussed how monetary theory could be represented by an hydraulic model. James Meade
I'm not a communist, just a media theorist. Douglas Rushkoff
I can assure you that no string theorist would be interested in working on string theory if it were somehow permanently beyond testability. That would no longer be doing science. Brian Greene