Is Morality a Sham?

Morality is supposed to be of the utmost importance. We're supposed to do the "right" thing even when we would benefit from doing the "wrong" thing. But why? Do we really have good reason to be moral, or is this just an illusion - an outdated superstition, or a remnant of our evolutionary history, or even a lie that some people use to control others? Is morality based on objective facts like mathematics or science, or is it just a matter of personal taste, like whether you prefer coffee or tea? And if morality is just an illusion or a matter of taste, should we take it less seriously than we do? We will explore these and similar questions with the help of philosophical texts both ancient and modern. Prior experience with philosophy is welcome but by no means required.