The transport of magmas in the Earth is a phenomenon of first-order importance to the physical, chemical, and climatological evolution of our planet. Volcanism, in particular, can have dramatic impact on human lives, not only as an immediate environmental hazard but also as a longer-term influence on climate. The transport properties of magma—that is, physical flow in response to stress and diffusion of dissolved components as a result of chemical gradients—have been the subject of intensive study in recent decades. Nevertheless, the complexity of these physical and chemical responses requires an even more generalized picture of magma transport than is currently available. The emerging view of magma transport incorporates melt dynamics, non-Newtonian flow, brittle failure, and the fundamental nature of the glassy and liquid states.