We show a lot of respect for science today. To back up our claims, we tend to appeal to scientific methods. It seems that we all agree that these methods are effective for gaining the truth. We can ask why science has its special status as a supplier of knowledge about our external world and our bodies. Of course, one should not always trust what scientists say. Nonetheless, epistemological justification of scientific claims is really a big project for philosophers of science. Philosophers of science are interested in knowing how science proves what it does claim and why it gives us good reasons to take these claims seriously. These questions are epistemological questions. Epistemology is a branch of philosophy which deals with knowledge claims and justification. Besides epistemological questions, metaphysical and ethical issues in science are worthy of philosophical scrutiny. This paper gives a short survey of these intellectually demanding issues.