sym- para- meta- dia- |||| -bolism

let us welcome four terms based on the quality of throwing (greek: ballein). 

throwing: a move that in its naive, unreflected joy- and gameful manner might be significant for the mental shape in this day and age. for setting these four friends grammatically congruent, thus more comparable with each other, they are presented in their most substantival, petrified state, the noun, which we could call even the nominal systematization of themselves. 

we see them permutating: freezing down from meaning the living action - the ballein - via describing a state down to the thing, the concept, the -ism. although these terms are used in quite contradictive ways of understanding, we can draw some general outline about their relationship - just by a simple description of what they are talking about:

symbolism deals with the equivalence of a sign and its reference. word and reality are thrown sensibly together with each other.
the idea of parabolism is to unify energies - e.g. rays - flowing in parallel direction into one single focus. they are thrown sensibly the same way.
metabolism means the living exchange of energies, the transformation from one state of matter into another, either by splitting it up or by building it up, likely called destructive / constructive metabolism: throwing a certain something sensibly into another position or constellation.
diabolism is jumbling energies and matters confusingly. or even destructively. they will be thrown in a chaotic way - which finally means to withdraw.