these words have been transplanted from simple to figurative speech. they are applied to all the parts of the body that are in motion, in action — the force of the heart, which some have made four hundred pounds, and some three ounces; the force of the viscera, the lungs, the voice; the force of the arm.

the metaphor which has transported these words into morals has made them express a cardinal virtue. strength, in this sense, is the courage to support adversity, and to undertake virtuous and difficult actions; it is the “animi fortitudo.”

the strength of the mind is penetration and depth —“ingenii vis.” nature gives it as she gives that of the body; moderate labor increases and excessive labor diminishes it.

the force of an argument consists in a clear exposition of clearly-exhibited proofs, and a just conclusion: with mathematical theorems it has nothing to do; because the evidence of a demonstration can be made neither more nor less; only it may be arrived at by a longer or a shorter path — a simpler or more complicated method. it is in doubtful questions that the force of reasoning is truly applicable.

the force of eloquence is not merely a train of just and vigorous reasoning, which is not incompatible with dryness; this force requires floridity, striking images, and energetic expressions. thus it has been said, that the sermons of bourdaloue have force, those of massillon more elegance. verses may have strength, and want every other beauty. the strength of a line in our language consists principally in saying something in each hemistich.

strength in painting is the expression of the muscles, which, by feeling touches, are made to appear under the flesh that covers them. there is too much strength when the muscles are too strongly articulated. the attitudes of the combatants have great strength in the battles of constantine, drawn by raphael and julio romano; and in those of c?sar, painted by lebrun. inordinate strength is harsh in painting and bombastic in poetry.

some philosophers have asserted that force is a property inherent in matter; that each invisible particle, or rather monad, is endowed with an active force; but it would be as difficult to demonstrate this assertion as it would be to prove that whiteness is a quality inherent in matter, as the trevoux dictionary says in the article “inherent.”

the strength of every animal has arrived at the highest when the animal has attained its full growth. it decreases when the muscles no longer receive the same quantity of nourishment: and this quantity ceases to be the same when the animal spirits no longer communicate to the muscles their accustomed motion. it is probable that the animal spirits are of fire, inasmuch as old men want motion and strength in proportion as they want warmth.