Justifying your thesis
I know it is hard enough actually stating what your thesis is, but once you have articulated it, you then have to be able to convince the world that it is important enough to be worthy of 3 years' consideration, and that what you have found is a substantial contribution to the world's knowledge.
One of the most serious concerns relates to the need for a sound justification that the research topic is substantive enough to satisfy the requirement that the thesis makes a substantial and original contribution to scholarship.
One way of making this justification is to demonstrate, through your literature review, that other people have identified the gap in knowledge that you are intending to fill, that they care about knowing the answer, and that the question is contemporary and relevant. In this way, citation becomes a powerful ally in your construction of a sound argument.