This issue opens an inquiry into the tension between solidity and fluidity. This tension is ingrained in the Western intellectual tradition and informs theoretical debates across the sciences and humanities. In physics, solid is one phase of matter, alongside liquid, gas and plasma. This, however, assumes all matter to be particulate. Reversing the relation between statics and dynamics, we argue to the contrary, that matter exists as continuous flux. It is both solid and fluid. What difference would it make were (...) we to start from our inescapable participation in a world of solid fluids? Is solid fluidity a condition of being in the midst of things, or of intermediacy on a solid-fluid continuum? Does the world appear fluid in the process of its formation, but solid when you look back on things already formed? Here we open new paths for theorizing matter and meaning at a time of ecological crisis. (shrink)