reasoning
[C/U] Both
This term describes the mental machinery used to bridge the gap between a known fact and a new conclusion. It carries a connotation of structure and deliberation, suggesting a step-by-step intellectual process rather than a sudden intuition or a random guess. In professional or academic settings, it is used to validate a claim. When someone questions your reasoning, they are not necessarily questioning your conclusion, but rather the validity of the path you took to get there.
Uncountable when referring to the general mental process of thinking logically. Countable when referring to a specific chain of logic or a particular argument used to justify a decision.