In statistical mechanics, the possibility of spontaneous transitions between
the different states of an isolated system are usually characterized by the
increase of entropy via the second law of thermodynamics. However, a stronger
criterion that holds for systems obeying a master equation, the so-called
principle of increasing mixing character, has also been proposed to describe
these transitions. This principle relies on a more fundamental notion of
disorder, which is described through the majorization preorder. Here, we show
that, when replacing entropy by disorder, one requires a countably infinite
family of entropy-like functions in order to obtain the corresponding second
law of thermodynamics. Hence, regarding complexity, disorder goes well beyond
the second law of thermodynamics. Furthermore, we prove an analogous result
holds for the transitions of a system that is coupled to a heat bath