Evidence before belief or belief before evidence?
A classic blunder in logic / reasoning / critical thinking is to form a conclusion before examining evidence. Doing so indicates that a decision is made BEFORE considering applicable evidence – then looking for evidence to support the decision / conclusion.
That combines Jumping to Conclusions and Confirmation Bias (perhaps with Wishful Thinking added).
Jumping to conclusions (officially the jumping to conclusions bias, often abbreviated as JTC, and also referred to as the inference-observation confusion) is a psychological term referring to a communication obstacle where one "judge[s] or decide[s] something without having all the facts; to reach unwarranted conclusions"
https://en.wikipedia.org/wiki/Jumping_to_conclusions
Confirmation bias, also called confirmatory bias or myside bias,[Note 1] is the tendency to search for, interpret, favor, and recall information in a way that confirms one's preexisting beliefs or hypotheses, while giving disproportionately less consideration to alternative possibilities. It is a type of cognitive bias and a systematic error of inductive reasoning. People display this bias when they gather or remember information selectively, or when they interpret it in a biased way. The effect is stronger for emotionally charged issues and for deeply entrenched beliefs. People also tend to interpret ambiguous evidence as supporting their existing position. Biased search, interpretation and memory have been invoked to explain attitude polarization (when a disagreement becomes more extreme even though the different parties are exposed to the same evidence), belief perseverance (when beliefs persist after the evidence for them is shown to be false), the irrational primacy effect (a greater reliance on information encountered early in a series) and illusory correlation (when people falsely perceive an association between two events or situations).
https://en.wikipedia.org/wiki/Confirmation_bias
An example is to decide a person's guilt or innocence before evidence is presented and considered – an emotional response, not a reasoned decision based on all available information.Wishful thinking is the formation of beliefs and making decisions according to what might be pleasing to imagine instead of by appealing to evidence, rationality, or reality. It is a product of resolving conflicts between belief and desire.
https://en.wikipedia.org/wiki/Wishful_thinking
Notice that this also covers all cases in which 'You must believe before you can see the evidence'.
