ABSTRACT
This chapter examines some historical cases of how contradictions between theory and observations have been resolved. Cases in which the theory has been abandoned in its entirety. Cases in which the theory has been modified. Cases in which some auxiliary assumption has been changed, thereby permitting the theory to be maintained in its entirety. The historical case of the Michelson and Morley experiment is the classic example. It will be recalled that Lorentz and Fitzgerald showed that a belief in the truth of the ether theory could be maintained by changing the previous auxiliary assumption that a measuring rod does not alter in length with changes in its velocity. Newton's laws failed to predict accurately the correct orbit of Uranus around the Sun. Consider Darwin's theory of evolution, which asserts that the off-spring of any organism tends to differ from its parent in small random ways.
