position, or authority of an individual or  institution as the primary basis for a conclusion,  

without sufficient supporting evidence. This fallacy arises when a conclusion is  

based mainly on an authority's endorsement,  not on solid evidence or analysis. 

It's problematic because authorities can  be mistaken, and history shows experts have  

held now-disproven beliefs. Focusing on who  makes the argument rather than its intrinsic  

merits can lead to neglecting actual evidence. Authorities can also be misquoted or influenced by  

biases, leading to misinformation. Furthermore,  reliance on authority discourages independent  

thinking and critical analysis, promoting  acceptance of ideas without proper scrutiny. 

Everyday Example: Consider someone arguing  

about a health trend said: "This diet must be  effective because a famous scientist follows it."