The essence of simplicity is economical i.e. simplicity can only be accomplished through economical activities. By ‘economical’ I mean characterised by the academic sense in which we allocate scarce resources that have alternative uses.
There are only four such resources that exist: space, time, matter and knowledge. Everything in the universe falls into one of these four.
Anything can be simplified give an infinite amount of resources and it is scarcity of these resources that limits our efforts by exacting costs when aiming towards simplicity. It might sound counterintuitive to think that even the idea of a simple idea is constrained by these four resources until one realises that given an infinite time any concept can be reduced ad nauseam but this only serves to highlight that time is finite as far as any observer is concerned. As Thomas Sowell has rightly pointed out in Basic Economics “there are no solutions, only trade offs”.
For this reason there are practical limits in achieving simplicity for the simple fact that there are finite resources. One cannot expect to infinitely simplify something because the universe does not admit actual infinities.
An idea is simple if it can be appreciated or conveyed within a reasonable amount of time and in reference to a reasonable assembly of prior ideas. Notice the relative use of the terms ‘reasonable’ indicating that a lot depends on the particular circumstances. There is no such thing as universal simplicity much as there is no such thing as absolute simplicity.
Aspirations towards simplicity are inherently conservative i.e. by imbuing some design with simplicity we are attaining towards conserving some resource. For example, a simple tool is one that can be used with a relatively short learning curve and which relies on few input resources.
Complexity exists. It follows that there are entities that resist simplification. We have no recourse but to either avoid them by employing heuristics (good guesses) or paying the true price they exact. For example, the only way to evaluate electrical circuit parameters is through solving simultaneous equations, which are notoriously computationally expensive. Therefore, solving electrical circuit parameters are inherently complex. However, this might only be the case because of the chosen paradigm. It could be that on a different solution paradigm, perhaps one we are yet to discover, that such problems are dirt cheap, though, as is often the case, there might be a not-so-small price in switching paradigms.
My theistic presuppositions, evinced by Proverbs 25:2, inform me that our advances towards progress are teleologically-bound. It is no accident that some things are simple and others are complex.
Whenever you get simplicity someone has had to do the work of 'hiding' complexity. Two points from this:
Realise that complexity doesn't go away! It has to be hidden.
What is the distinction between simplicity, complexity and chaos?