Full Idea
Syntactical methods of proof (e.g.'natural deduction') have regard only to the formal structure of premises and conclusions, whereas semantic methods (e.g. truth-tables) consider their possible interpretations as expressing true or false propositions.
Gist of Idea
Syntactical methods of proof need only structure, where semantic methods (truth-tables) need truth
Source
E.J. Lowe (Introduction to the Philosophy of Mind [2000], Ch. 8)
Book Reference
Lowe,E.J.: 'Introduction to the Philosophy of Mind' [CUP 2000], p.203
A Reaction
This is highly significant, because the first method of reasoning could be mechanical, whereas the second requires truth, and hence meaning, and hence (presumably) consciousness. Is full rationality possible with 'natural deduction'?