reasoning

noun

I can't quite follow your reasoning |

the reasoning behind their decisions:

thinking, line of thought, train of thought, thought, thought process, logic, reason, rationality, analysis, interpretation, explanation, deduction, rationalization, argumentation;

reasons, rationale, arguments, premises, case;

supposition, hypothesis, thesis;

Philosophy dialectics;

rare cerebration, ratiocination, mentation.

reason Oxford Dictionary of English