 There are various ways to cope with this problem. One could try to unmask it as a pseudo-problem. Or one could try to accept the problem as part of the usual way science works, albeit not in the clean manner philosophers would like it. The structuralistic programs, however, agree that this is a non-trivial problem to be solved and devise meta-theoretical machinery to enable its solution. They further agree on dividing the vocabulary of the theory \(T\) into \(T\)-theoretical and \(T\)-non-theoretical terms, the latter being provided from outside the theory. 