ABSTRACT
A necessary proposition is true by virtue of the nature of things, it expresses the essence of things. An analytic proposition is true by virtue o f its meaning or, when in the subject-predicate form, if the predicate is contained in the meaning of the subject. An a priori proposition is one which can be known without any appeal to the particular facts of experience. These crude dictionary definitions are sufficient to bring out the distinction that necessity is a metaphysical concept, analyticity a linguistic concept, and apriority an epistemo logical concept. Of the three concepts, necessity (or possibility) has the advantage of being an everyday concept, while the other two were invented by philosophers. Nonetheless, they are intimately connected with the nontechnical concepts of meaning and experience.
