Locke also believed that objective knowledege could be obtained by inferring. He believed that by having full knowledge of our biological and phychological limitations, as well as acknowledging that what we DO percieve MUST be a reflection of the objective, that we could 'guess' the objective in a way. The example used often is that we perceive light as colour, but we have inferred that the 'objective' state of colour has something to do with split d-orbits and the excitation of electrons, releasing photons of light.