6. “As the intension of a term is increased its extension is decreased and _vice versa_,” is a statement of the Law of Variation in the extension and intension of terms. 6a. The law of variation applies only to a series of terms representing notions of the same class or family, the words being arranged in a species-genus order. The increase and decrease of the extension and intension of a series is not proportional. 6b. The law of variation is best explained by using two triangles, one super-imposed upon the other vertex to base and base to vertex. =9. ILLUSTRATIVE EXERCISES.= 1a. Employ the following terms in extension――European, flower, term, truth. { Russian European { Englishman { Scotchman { lily flower { rose { pansy { singular term { distributive { collective { Truth has no extension. truth { Since it refers to a { quality only, it is { non-connotative. 1b. Employ the following in extension――grain, rock, soil, precious stone. 2a. Use intensionally bird, quadruped, letter, John. { two feet bird { ability to fly { feathers { four feet quadruped { back bone { hairy covering { heading letter { body { complimentary close { John has no intension. John { Since it refers to { an object only, it is { non-connotative. 2b. Use the following in intension――word, table, purity, government. 3a. The use of a term in extension follows when attempting to answer two questions: First, what are the kinds? Second, to what objects may the term be applied? Make application of this with reference to the term _man_. 1. What are the kinds of men? Caucasian, Malay, Mongolian, Ethiopian, Redman. 2. To what objects does the term _man_ refer? George Washington, Chas. Hughes, John Smith. In both 1 and 2 the word _man_ is used to denote objects, hence it is employed in extension. 3b. Use the term _vegetable_ in extension by answering the two questions in 3a. 4a. Decrease one by one the qualities of some common object with a view of noting how when the intension is decreased the extension is increased. _Intension_ _Extension_ binding } { leaves } { cover } { school arithmetic printed matter } { designed for instruction } { instruction in arithmetic } { binding } { leaves } { school arithmetic cover } { school grammar printed matter } { school speller, etc. designed for instruction } {