Skepticism
Skepticism is the philosophical attitude of withholding belief until evidence is sufficient. In moderation it’s a core part of Critical Thinking, a healthy default of “show me why.”
When it goes wrong
Reflexive or selective skepticism (doubting only the claims you don’t like) looks like critical thinking but isn’t. It dismisses the inconvenient without doing the work of refuting it.
A genuine skeptic applies the same standard of evidence to all claims, including their own.