Philosophical thinking is argumentative. It does not merely assert views, but attempts to establish them. Your essay should likewise set out to establish a stand in the context of a problem. The problem and your stand towards it may focus on a point of interpretation, on underlying assumptions, on further implications, on a critical assessment, on a critical defence. Whatever your focus, in the introduction state the general issue or problem and your intent or direction in the essay. The reader should have a clear idea where philosophically you are heading. For example, if your topic is Plato's theory of virtue and what you find troublesome is his claim that knowledge equals virtue, your introduction may look like this:
In the Republic Plato