But every truth always remains contingent on some unknown and unknowable variable not yet taken into account

A very good piece, Assessing a Claim: Is San Francisco's Shoplifting Problem Fake? by Resident Contrarian (RC).  He is responding to a blogger, Applied Divinity Studies (ADS), who posted a piece making a series of arguments and reaching a conclusion, San Francisco Shoplifting: Much More Than You Wanted to Know.

ADS concludes that there are good reasons to question the storyline indicating that there is a crimewave in San Francisco driven by lenient charging laws and by a lenient District Attorney.  He makes the argument in the standard Classical Liberal fashion, deploying argument, reason, logic and empirical evidence to conclude that there are good grounds for doubting that there is an epidemic of shoplifting and that, even if there were, it cannot be attributed to charging laws and DA actions.  

RC, in contrast, but also using argument, reason, logic and empirical evidence, concludes that we simply do not know.  We do not know whether there is an epidemic of shoplifting and we do not know what the primary causal contributors might be.

RC's main point is that ADS' argument is itself not strong.  Or even strong at all.  It is weak tea.  He faults ADS for leaving an impression that a conclusion can be arrived at when the only supportable conclusion is that we cannot be certain.

Both arguments are calm and plausible, though I favor RC's position.

And their arguments are representative of all complex, dynamic, chaotic, multiple, loosely coupled non-linear systems, i.e. all human systems.

They are incredibly difficult to comprehend both in terms of outcomes as well as in terms of causal mechanisms.  What Gerald M. Weinberg, in An Introduction to General Systems Thinking, refers to as systems of Organized Complexity.  Systems which have mechanistic attributes of direct cause and effect  but which cannot be explained solely through mechanistic analysis but which also are insufficiently random to be understood simply through statistical analysis either.  Organized Complexity.

As we pick off the low hanging fruit of mechanistic systems and statistically understandable systems, we are increasingly left with the perplexity of human systems manifesting organized complexity.  A state in which we are always suspended between confident assertion and deep uncertainty simultaneously.  The Schrödinger's cat of Plausibility.

The San Francisco example is the tip of the iceberg.  Is there an epidemic of black on Asian violence in big cities?  News media outlets suggest so, but really?  It is plausible and I don't know what the answer is with any great confidence.  Have public schools been completely taken over by autocratic critical race theorists subverting parents?  News media outlets suggest so, but really?  It is plausible and I don't know what the answer is with any great confidence.  Are male to female trans athletes bringing down women's competitive sports?  News media outlets suggest so, but really?  It is plausible and I don't know what the answer is with any great confidence.

On these and innumerable other issues, we are trapped by Organized Complexity and suspended with Schrödinger's cat in a mesh of Plausibility.

Sometimes answers can be arrived at through sheer diligent investigative and analytical work but even so, opinion, bias, and ideological conviction still undermine a truly confident conclusion.  

Using common sense and finding other analytical thinkers who seek truth with logic, argument, reason and humility ends up being the fastest and best supplement to one's own efforts.  

But every truth always remains contingent on some unknown and unknowable variable not yet taken into account.  We can only arrive at what is usefully true and that which is least inconsistent with the facts, logic and reason with which we are most confident.