  Large-eddy simulations (LES) are widely-used for computing high Reynolds
number turbulent flows. Spatial filtering theory for LES is not without its
shortcomings, including how to define filtering for wall-bounded flows,
commutation errors for non-uniform filters, and extensibility to flows with
additional complexity, such as multiphase flows. In this paper, the theory for
LES is reimagined using a coarsening procedure that imitates nature. This
physics-inspired approach is equivalent to Gaussian filtering for single-phase
wall-free flows but opens up new insights for modeling even in that simple
case. Boundaries and nonuniform resolution can be treated seemlessly in this
framework without commutation errors, and the divergence-free condition is
retained for incompressible flows. An alternative to the Germano identity is
introduced and used to define a dynamic procedure without the need for a test
filter. Potential extensions to more complex physics are briefly discussed.
