_Spirit, i.e. Breath or Wind, is a metaphorical name—implying subtleness, invisibility, ubiquitousness and life-giving power—given to the ultimate Cause of Force; and hence sometimes to the Cause of beneficent Force in the Universe, i.e. God; sometimes to the Cause of Force in the human individual; more rarely to the Cause or Causes of maleficent Forces in the Universe._ v. Matter The existence of Matter has never been proved; and it is nothing but a hypothesis. All the phenomena called “material” might be explained, without Matter, by the hypothesis of a number of centres of force. The _raison d’être_ of Matter is the notion of tangibility. But scientific men now tell us that no atom ever touches another. If this be so, scientific tangibility disappears and the _raison d’être_ of Matter disappears, with it. But it is so natural a figment that we shall all probably talk about it, and most of us probably will believe in it, until human nature is very much changed. Matter cannot be defined positively except by repeating, in some disguise, the word to be defined, as thus:— _Material, or Matter, is a name given to an unascertained and hypothetical “material,” “matter,”_ “_substance,” or “fundamental stuff,” of which we commonly imagine all objects of sensation to be composed._ vi. Nature 1. _Nature means sometimes the (1) ordinary, or (2) orderly course of things apart from the present and direct intervention of human Will; sometimes the (3) ordinary or (4) orderly course of humanity; sometimes the (5) ordinary or (6) orderly course of all things._ 2. _Law of Nature is a metaphorical name for a frequently observed sequence of phenomena (apart from human Will) implying, to some minds, regularity; to others, absolute invariability._ 3. _Miracle means a supposed suspension of a Sequence, or Law, of Nature; Marvel, or Mighty Work, means a rare Sequence of Nature, in which great Effects are produced by Causes seemingly, but not really, inadequate._ 4. _“Supernatural” is the name given, in these letters, to the existence of a God; and to His creation and continuous development of all things: the divine action being regarded, not as contrary to Nature, but as above Nature; not as suspending the sequences of Nature, but as originating and supporting them._ vii. Will _The Will is the power of giving to some one of our desires, or to some one group of compatible desires, permanent predominance over the rest._ An addition might be suggested: “the power of controlling our desires.” But we appear never to control our desires except by enthroning some one desire (or group of desires)—whether it be the desire to gain power, to ruin an enemy, to do right, or to serve God. viii. Attention