The logical form of a sentence is the structure, shareable with other sentences, responsible for its powers in inferences. That is, its logical form determines the way in which it can be validly deduced from other sentences, and the way other sentences can validly be deduced from sets of premises that include it. Obviously there is something common to the argument, ‘All men are mortal, Socrates is a man, so Socrates is mortal’, and ‘All horses bite, Eclipse is a horse, so Eclipse bites’. This common form may be revealed by abstracting away from the different subject-matter, and seeing each argument as of the form ‘All Fs are G; a is F; so a is G’. The ‘symbols’ of symbolic logic simply represent such common forms and the methods of combining elements to make up sentences. It is frequently controversial to what extent reduction to simple forms is possible, and how much hidden structure it is fruitful to look for, in order to reveal similar logical forms under the surface diversities of ordin-ary language.
Philosophy dictionary. Academic. 2011.