At its heart, 28 Days Later is a philosophical work about the nature of civilisation, slowly worked through from the lowest end expectation to the highest. It may seem weighty fare for a zombie flick, but it's hardly the first time the genre has been used for discussing the nature of life: Zombies work very neatly for this as a refutation of life! In the end, the film essentially opts for the Three Bears logic of civilisation: Human contact, somewhere between mere survival and the institution, is at the heart of civilisation.