The issue of absolute certainty about a certain knowledge or fact is traced back to traditional Aristotelian logic. His works are the oldest known official studies of knowledge that were ever found that still share a lot in common with current theory of logic. Basically, there are two basic ways a person can decide if a certain assumption is a fact or it has to remain an assumption – through deductive and inductive reasoning. Speaking about the subject of certainty in knowledge, we will mention deductive reasoning. Then we will move our focus to present-day inductive reasoning that is established on 20th century association.

Aristotle’s subject of logic progresses essentially around deduction. The primary principle of deduction is that assurance about a given fact can be guaranteed if it is resulting from the necessity. The essential circumstances are called the premise, whereas the result is the conclusion. Even though Aristotle accepted induction as the kind of knowledge his works were fundamentally centered on deduction. To make sure that deduction works, the consequences of the necessity have to be essentially diverse from what has been supposed. By itself, two identical conclusions can not exist. Grounds that superfluous or inconsistent are barred from the reasoning. For a time, there was a belief that our sensory data – color, sounds and the like –are possible to be acquainted with, while the rest of our acquaintance can be inferred to with use of reasoning. It has been pointed out that differentiations between physical and mental worlds are illogical and can be condensed to simple forms. There was a concept that an fundamental usual language statements’ “logical form” could be searched in the analysis and that way uncertainty in language could be prevented. For example, by examining all various meanings of a word and giving them reasonable notations, a person can also learn other ontologically major differences being aware of the accurate logical form of a specified sentence. The method of analysis contains valuation of problematic presuppositions and evidence by using first order logic and decrease of sentence structure to the primary “logical form”.
via