Reasoning.
Synonyms:
argument, argumentation, debate, ratiocination.
Argumentation and debate, in the ordinary use of the words, suppose two parties alleging reasons for and against a proposition; the same idea appears figuratively when we speak of a debate or an argument with oneself, or of a debate between reason and conscience. Reasoning may be the act of one alone, as it is simply the orderly setting forth of reasons, whether for the instruction of inquirers, the confuting of opponents, or the clear establishment of truth for oneself. Reasoning may be either deductive or inductive. Argument or argumentation was formerly used of deductive reasoning only. With the rise of the inductive philosophy these words have come to be applied to inductive processes also; but while reasoning may be informal or even (as far as tracing its processes is concerned) unconscious, argument and argumentation strictly imply logical form. Reasoning, as denoting a process, is a broader term than reason or argument; many arguments or reasons may be included in a single chain of reasoning.