Causality is a corollary of identity. At the most fundamental level of physics, quarks, fermions and the other elementary particles do what they do. At the everyday level, the objects we perceive also do what they do. If you put ice cubes in water they melt. And the melting of ice is ultimately a very, very complex movement of quarks (i.e., energy is transferred from the water to the ice, breaking down the ice’s structure; if we zoom in further the energy transfer consists of vibrating molecules bouncing off each other). We have necessary micro-events which are organized into the necessary macro-events we perceive.