Ideology is a tool, a technology of descriptive (i.e. algorithmic) information compression and generalised (over-)simplification through which complex realities and observed facts are rendered comprehensible. Decisions, evaluations and strategic planning for continuity (of self, of organisations, of civilisation) are facilitated by compression.
Having cultivated or procedurally-defined the conceptual boundaries and adaptive grammars of such systems of interpretation, these information artefacts and entities tend towards viral self-propagation; they generate “their own weather systems”, expectations, deviations from (non-partisan) reality. Ideology is a mnemonic tool and framework through which reality (as facts) is parsed but which simultaneously performs a (literal) polarising filtration of what facts or opinions are able to pass through the filter. Truth is relativised in this way.
When ideology itself becomes the artefact that is (recursively) passed through a polarising filter of ideology, all bets (and forecasts, or strategies and plausible resolutions) are off. The tools we use to reduce the complexity of the world to intelligible grammars are those that also obscure the intrinsic failures of those tools and grammars.