Читать книгу Twentieth-Century Philosophy of Science: A History (Third Edition) - Thomas J. Hickey - Страница 79

Theory language is defined pragmatically, but theories are individuated semantically.

Theories are individuated semantically in either of two ways:

Firstly different expressions are different theories, because they address different subjects.

Different theory expressions having different test designs producing different measurements or observations are different theories with different subjects.

Secondly different expressions are different theories, because each makes contrary claims about the same subject.

The test-design language defines the subject and is the same for all of such contrary theories.