  The energy-minimization multiscale (EMMS) principle of compromise in
competition is believed to be generally applicable for all mesoscale problems
at different levels in the real world, spanning from elementary particles to
the universe. This stimulated a fundamental proposition of the concept of
mesoscience. This article discusses a potential universality of the
regime-specific multi-objective variational feature of this underlying
principle through case studies in chemical engineering. It is also elucidated
why the currently available variational principles are not applicable to the
mesoscale problems. The paper concludes with prospects on future study.
