In moral philosophy, we seek to determine which acts are right and wrong and why. One common method employed for making these determinations is known as reflective equilibrium . The method is, in some respects, analogous to the scientific method. So, let's be sure that we first understand how the scientific method works.
Scientists begin by observing natural phenomena.
They then try to formulate theories which can account for their observations. These theories should not only be able to explain our past observations but also predict new, previously unobserved phenomena. Hence, these theories can be tested by making new observations and then comparing these observations with the theory's predictions. Sometimes these new observations are not what the theory predicted. When this happens usually the theory is rejected or at least revised.