in theory; on paper / in a theoretical manner

(physics) the description of natural phenomena in mathematical form, especially in order to derive fundamental laws of nature and to derive conclusions from these laws

Any theory attempting to explain the process by which individuals explain the causes of behaviour and events.

A male given name from the Germanic languages / A surname originating as a patronymic.

the theory that changes in prices and the value of money vary with changes in the amount of money in circulation

(ecology) The theory that mitochondria and chloroplasts, which are organelles of eukaryotic cells, originated as independent organisms.

(mathematics) A branch of mathematical analysis, concerned with the theory of integration, that generalizes the intuitive notions of length, area and volume.

(computer science) The study and classification of decision problems by the computational resources—such as time and space—needed by the programs that solve the problems.

The informal theory that stock market prices move in the same direction as the hemline of women's skirts, short skirts being considered bullish and long skirts bearish.

(biology) The scientific theory that all living organisms are made of cells as the smallest functional unit.