Abstract: One of the many unfortunate results of the long-lived misconception that Marx was a “determinist” is a lack of engagement with his ideas of necessity and negation. Reading the Grundrisse's famous comments on the annihilation of space by time, I trace the Hegelian roots of these concepts to show that for both Marx ahd Hegel, negation is the very act of critique itself, and necessity is properly understood not as the force of history, but as the object of historical explanation–what makes things the way they are and not another. It is therefore crucial to critical geography's efforts to identify the possibilities for social change, for that analysis must be predicated on an understanding for how things have emerged in their present form, i.e. the one we have to work with. I argue that a negative geography of necessity is the essential basis for anything we might call a communist geography, a geography of “the real movement which abolishes the present state of things”.