theorist
n.someone who develops ideas to explain how something works or why something happens. They focus on the rules and logic of a subject rather than the practical work.
n.a person who develops or investigates the underlying principles and abstract frameworks of a particular subject. Often contrasted with a practitioner or an experimentalist.
“The theorist spent years developing a new model for the economy.”
“While the engineers built the prototype, the theorist focused on the mathematical laws that made the design possible.”
“A political theorist might spend a lifetime analyzing the concept of justice without ever holding public office or participating in a campaign.”
Often followed by 'of' to specify a field, such as a 'theorist of international relations'.
“The Mrs Stern of the title is the married name of Hannah Arendt , the political theorist much remembered for her “banality of evil” insight.”
“B urke was not the only 18th-century theorist to champion politeness, friendship, moderation and reasonableness.”
From theory + -ist.
Etymology adapted from Wiktionary, available under CC BY-SA 4.0.