Professor S. F. Barker has recently argued that the theory of the status of theoretical concepts in natural science put forward by Hempel and Braithwaite is mistaken. Essentially this “formalistic” theory says that these concepts “take on” meaning from their place in a total theoretical system which as a whole implies testable observation statements. In the paper it is argued that Barker's criticism of the Hempel-Braithwaite theory is mistaken because (a) he does not sufficiently consider the operative empirical restrictions on concept formation in scientific theorizing, and (b) his criticisms are based on an acceptance of a narrow empiricism which would reject most existing theoretical natural science as empirically meaningless.