The role of Auxiliary Assumptions:

• The Quine-Duhem Thesis

  • The symmetry between falsification and verification is recovered when we take into account the role of auxiliary assumptions (A) of the theory (T):

• If the predicted observation (O) turns out to be false, we can deduce only that something is wrong with the conjunction, (T and A); we cannot determine from the premises that it is T rather than A that is false.