The history of the word temperance from the Greek εγκρατεια stems from might, power, and victory, so accents, at least to my mind, the special value of valour and moderation - juxtaposed as they are against possibly destructive strength. Sometimes it seems that there is a certain logic to begin learning with the deprivations of wisdom, so we know what we are striving towards. In this way, Ruskin begins his Deucalion by writing, "the young student should first learn the myths of betrayal and redemption as the Spirit which moved on the face of the wide first waters, taught to the heathen world." In other words, as an old monk once said years ago, first give them a spanking, then they can start to talk about humaneness.
For there is something in every single person's nature that is best overcome, hence the necessity of 'strength' in temperance. Strength is the difference between the straw and brick door when the wolf comes by huffing. "Intemperance, by depriving us of wisdom, and confounding the notions of good and evil, forces us to elect the evil instead of the good," Anthon writes. In metallurgy, tempering is the process used to increase the toughness of a metal, the resilience of glass. Man, too, needs toughening up.
Kurt Hahn was a Victorian educator who believed it necessary for people to toughen up when young. He found physical training particularly effective at instilling discipline and determination. In addition to listing "Six Declines of Modern Youth" - including the "Decline of Memory and Imagination due to the confused restlessness of modern life" - he outlined many learning principles ranging from self discovery, to learning to turn disabilities into opportunities, to the understanding that "we are crew, not passengers." These are the kinds of lessons that may strengthen a person in the good life.
"The good ... is that which is useful to aid us in obtaining that highest end, happiness of life. ... this happiness is not perceived by reason of external goods, or those presented by change, but only those goods which man has acquired for himself by toil, industry, exertion, and exercise of his natural powers, that is, by good and virtuous qualities," writes Anthon. Surely that requires strength in an age, to paraphrase Hahn, that weakens compassion through haste. In an age that has lost the tradition of craftsmanship and thus led to the decline of skill and care.
I'd add, with the loss of tradition goes the song - if not of Homer, then at least of Guthrie, lyrics sung by Dylan, which all require an extant platform of shared experience, which is erased by modern restlessness and resulting postmodern fantasy, "discord ... due to two wars and general unhappiness" (via).
There is another tone to temper not yet mentioned: that of the reservoir of calm. Anthon, in the quote at the top of the post, wrote that our labours are to be undertaken cheerfully, in good faith - and also, not "overcome by weariness of toil or difficulty". I cannot help but see a hint of Taoism in that: the idea that one is to work, but harmoniously so that one is never working against but with; working without really working (force x distance).
Like when doing physical exercise, to breathe out during the strenuous movement is to discover a source of energy that is not in the muscles and pain and sweat.
Temperance presents us with ample fruits, Anthon instructs. There is nothing abstract about this strength! When one begins to see the fruits of good labour, one would never want to go about things any other way. A healthy person strives, naturally, for temperance, because it is in fact the easier, more pleasant way.