A man can do his best only by confidently seeking (and perpetually missing) an unattainable perfection.

An ever-green revolution implies the enhancement of productivity in perpetuity without associated ecological harm.

It appears that all that can be, is. The Creator’s hand does not appear to have been opened in order to give existence to a certain determinate number of species, but it seems that it has thrown out all at once a world of relative and non-relative creatures, an infinity of harmonic and contrary combinations and a perpetuity of destructions and replacements. What idea of power is not given us by this spectacle! What feeling of respect for its Author is not inspired in us by this view of the universe!

No place affords a more striking conviction of the vanity of human hopes than a publick library; for who can see the wall crouded on every side by mighty volumes, the works of laborious meditation, and accurate inquiry, now scarcely known but by the catalogue, and preserved only to encrease the pomp of learning, without considering how many hours have been wasted in vain endeavours, how often imagination has anticipated the praises of futurity, how many statues have risen to the eye of vanity, how many ideal converts have elevated zeal, how often wit has exulted in the eternal infamy of his antagonists, and dogmatism has delighted in the gradual advances of his authority, the immutability of his decrees, and the perpetuity of his power.
Non unquam dedit
Documenta fors majora, quam fragili loco
Starent superbi.
Seneca, Troades, II, 4-6
Insulting chance ne'er call'd with louder voice,
On swelling mortals to be proud no more.
Of the innumerable authors whose performances are thus treasured up in magnificent obscurity, most are forgotten, because they never deserved to be remembered, and owed the honours which they have once obtained, not to judgment or to genius, to labour or to art, but to the prejudice of faction, the stratagem of intrigue, or the servility of adulation.
Nothing is more common than to find men whose works are now totally neglected, mentioned with praises by their contemporaries, as the oracles of their age, and the legislators of science. Curiosity is naturally excited, their volumes after long enquiry are found, but seldom reward the labour of the search. Every period of time has produced these bubbles of artificial fame, which are kept up a while by the breath of fashion and then break at once and are annihilated. The learned often bewail the loss of ancient writers whose characters have survived their works; but perhaps if we could now retrieve them we should find them only the Granvilles, Montagus, Stepneys, and Sheffields of their time, and wonder by what infatuation or caprice they could be raised to notice.
It cannot, however, be denied, that many have sunk into oblivion, whom it were unjust to number with this despicable class. Various kinds of literary fame seem destined to various measures of duration. Some spread into exuberance with a very speedy growth, but soon wither and decay; some rise more slowly, but last long. Parnassus has its flowers of transient fragrance as well as its oaks of towering height, and its laurels of eternal verdure.

Science has its being in a perpetual mental restlessness.

The prodigious waste of human life occasioned by this perpetual struggle for room and food, was more than supplied by the mighty power of population, acting, in some degree, unshackled, from the constant habit of emigration.

The wintry clouds drop spangles on the mountains. If the thing occurred once in a century historians would chronicle and poets would sing of the event; but Nature, prodigal of beauty, rains down her hexagonal ice-stars year by year, forming layers yards in thickness. The summer sun thaws and partially consolidates the mass. Each winter's fall is covered by that of the ensuing one, and thus the snow layer of each year has to sustain an annually augmented weight. It is more and more compacted by the pressure, and ends by being converted into the ice of a true glacier, which stretches its frozen tongue far down beyond the limits of perpetual snow. The glaciers move, and through valleys they move like rivers.

We did not design our organization to operate in perpetuity. Consequently, our people were able to devote themselves exclusively to the task at hand, and had no reason to engage in independent empire-building.

Will we ever again be able to view a public object with civic dignity, unencumbered by commercial messages? Must city buses be fully painted as movable ads, lampposts smothered, taxis festooned, even seats in concert halls sold one by one to donors and embellished in perpetuity with their names on silver plaques?