The aim of this thesis is to present and motivate the relative modality view, whereby at least the non-logical alethic kinds of modality are mere relative forms of logical modality. The first chapter is devoted to presenting the relative modality view in general, providing a correct formulation, and considering some arguments for and against. The next chapter considers the particular challenges raised for the view by some essentialists. The third chapter turns to look at logical modality, the bedrock of the relative modality view, and presents an example of an account of logical necessity which suits it well. I argue that logical necessity is that necessity implicated in a deductively valid argument, and hence that its source is to be found in an account of the laws of logic. I argue that the laws of logic are constitutive-normative laws of thought. The fourth chapter takes a more historical turn. Here I argue that Kant can be understood as advocating a relative modality view, in particular for what he calls "real modality". In the fifth and final chapter I will draw on the conclusions of the preceding chapters to present a Kantian relative account of metaphysical necessity. Metaphysical necessity is that which follows, as a matter of logical necessity, from conditions on our having any experience of an objective world. I argue why this Kant-inspired kind of relative necessity is well-suited to play the role of metaphysical necessity, and consider how the view accommodates contemporary views about features of metaphysical necessity and its typical cases.