firmness comes from firm, and has a different signification from solidity and hardness; a squeezed cloth, a beaten negro, have firmness without being hard or solid.
it must always be remembered that modifications of the soul can only be expressed by physical images; we say firmness of soul, and of mind, which does not signify that they are harder or more solid than usual.
firmness is the exercise of mental courage; it means a decided resolution; while obstinacy, on the contrary, signifies blindness. those who praise the firmness of tacitus are not so much in the wrong as p. bouhours pretends; it is an accidental ill-chosen term, which expresses energy and strength of thought and of style. it may be said that la bruyère has a firm style, and that many other writers have only a hard one.