Deductive reasoning Deductive reasoning Deductive reasoning, also deductive logic, logical deduction is the process of reasoning from one or more statements (premises) to reach a logically certain conclusion. Deductive reasoning goes in the same direction as that of the conditionals, and links premises with conclusions. If all premises are true, the terms are clear, and the rules of deductive logic are followed, then the conclusion reached is necessarily true. Deductive reasoning (""top-down logic"") contrasts with inductive reasoning (""bottom-up logic"") in the following way; in deductive reasoning, a conclusion is reached reductively by applying general rules which hold over the entirety of a
First-order logic a common structure of ""a" is a philosopher". The variable "a" is instantiated as "Socrates" in the first sentence and is instantiated as "Plato" in the second sentence. While first-order logic allows for the use of predicates, such as "is a philosopher" in this example, propositional logic does not. Relationships between predicates can be stated using logical connectives. Consider, for example, the first-order formula "if "a" is a philosopher, then "a" is a scholar". This formula is a conditional statement with ""a" is a philosopher" as its hypothesis and ""a" is a scholar" as its conclusion. The truth of this