...to illustrate our rules and methods. In this respect logical calculations stand in marked contrast with those of mathematics, where economical devices...variations of popular language are so multitudinous, and the terms often so ambiguous, that the data may need careful consideration before they can be reduced...

...place, it does not seem to me that any contrivances at present known or likely to be discovered reallv deserve the name of logical machines. It is but a...process would involve four tolerably distinct steps. Ihere is, first, the statement of our data in accurate logical language. This step deserves to be reckoned,...