CONCEPT
Deduction
The mode of inference — the only one Peirce considered absolutely certain — that moves from general premises to particular conclusions with logical necessity, and the kind of thinking machines have always been able to perform.
Deduction, in Peirce's tripartite classification, is the mode of inference in which the conclusion is contained in the premises. If all instances of a class have a property, and this individual belongs to that class, then this individual has that property. The conclusion adds nothing that was not already implicit; it makes explicit what the premises already contained. Deduction is certain, but its certainty is purchased at the cost of sterility — it generates no new knowledge. It clarifies, it proves, it derives, but it does not discover. The entire output is folded into the input, like a letter inside an envelope. Peirce was clear in his 1887 essay on logical machines that deduction is precisely the kind of thinking that machines can perform, because its output is determined by its input.
In The You On AI Field Guide
Peirce wrote in 1887: "The secret of all reasoning machines is after all very simple. Whatever relation among the objects reasoned about