What are the point of conversion and departure between science and social science? Are the two sciences above use scientific methods? And what my opinion on this point? What do we mean when we say that we know some thing? What are the sources of knowledge? If we take the example of part of science that is medicine, we can know that there are different source of knowledge such as personal experience of our won bodies, observation of others, our families, friends" you do look ill", popular culture, bad cough and complementary health practice such as "holistic medicine." Medical knowledge of the general practitioner, we expect the doctor to have access to expert knowledge. This is socially sanctioned "because he describes drugs and treatment to which patients would not other wise have access." Evidence from "X-ray" diagnosis, experiments, observations, instruments, add new knowledge to the patient and the...