To confine our attention to terrestrial matters would be to limit the human spirit.
— Stephen Hawking

There is only one way to achieve happiness on this terrestrial ball, and that is to have either a clear conscience or none at all.
Ogden Nash terrestrial quote

An extra-terrestrial philosopher, who had watched a single youth up to the age of twenty-one and had never come across any other human being, might conclude that it is the nature of human beings to grow continually taller and wiser in an indefinite progress towards perfection; and this generalization would be just as well founded as the generalization which evolutionists base upon the previous history of this planet.
— Bertrand Russell

But the whim we have of happiness is somewhat thus. By certain valuations, and averages, of our own striking, we come upon some sort of average terrestrial lot; this we fancy belongs to us by nature, and of indefeasible rights. It is simple payment of our wages, of our deserts; requires neither thanks nor complaint. Foolish soul! What act of legislature was there that thou shouldst be happy? A little while ago thou hadst no right to be at all.
— Thomas Carlyle

Progress is man's mode of existence. The general life of the human race is called Progress, the collective stride of the human race is called Progress. Progress advances; it makes the great human and terrestrial journey towards the celestial and the divine; it has its halting places where it rallies the laggard troop, it has its stations where itmeditates, in the presence of some splendid Canaan suddenly unveiled on its horizon, it has its nights when it sleeps; and it is one of the poignant anxieties of the thinker that he sees the shadow resting on the human soul, and that he gropes in darkness without being able to awakenthat slumbering Progress.
— terrestrial quotation by Victor Hugo