First Sentence

"IN every instance in which we reason, in the strict sense of the word, i.e. make use of arguments, (I mean real, i.e. valid arguments,) whether for the sake of refuting an adversary, or of conveying instruction, or of satisfying our own minds on any point, whatever may be the subject we are engaged on, a certain process takes place in the mind which is one and the same in all cases, provided it be correctly conducted."