How to describe a person who comes to a conclusion without verifying the facts (please use a four-word idiom).

Subjective judgment: judging by imagination. Judge things subjectively rather than objectively.

Jump to conclusions: say what you have decided; Just jump to conclusions.

Assertion: Say a definite statement without thinking.

Catch the wind and catch the shadow: you can't catch the wind or the shadow. Metaphor has no factual basis for talking and doing things.

After a storm comes a calm: a metaphor for jumping to conclusions without seeing the facts clearly.

Nonsense: letter: let go, let go; Orpiment: Shi Ying, a yellow mineral used as a pigment. The ancients used yellow paper to write, and when they made mistakes, they rewrote it with orpiment. Metaphor regardless of the facts, just talk nonsense.