The answer, of course, is that great seventeenth-century physician of Norwich, Dr Thomas Browne. The words are to be found in Chapter V of his famous essay Hydriotaphia, better known perhaps as Urn Burial. Ansible's use of this quotation, in a casual, throw-away manner, is itself sufficient to disprove the oft-heard allegation that science-fiction freaks are ignorant slobs, unfit to do more than empty your dustbin.
I was first introduced to Thomas Browne about forty-six years ago, by William Styron. He used Urn Burial as the source for the title of his novel Lie Down in Darkness. Browne says this:
And since death must be the Lucina of life, and even pagans could doubt whether thus to live were to die; since our longest sun sets at right declensions and makes but winter arches, and therefore it cannot be long before we lie down in darkness and have our light in ashes; since the brother of death daily haunts us with dying mementoes, and time that grows old itself bids us hope no long duration -- diuturnity is a dream and folly of expectation.Better remember that, folks: diuturnity is a dream and folly of expectation. What that means is that you ain't gonna live for ever, so make the most of it while you can.
Urn Burial is a meditation upon the meaning of life and death. Browne's prose is dense, and for modern readers it is often quite difficult to understand. It is also patchy (in my view) and uneven. But read certain passages aloud and you will hear prose of a quality which has seldom been equalled. Virginia Woolf said that 'Few people love the writings of Sir Thomas Browne, but those who do are of the salt of the Earth.' So perhaps he's worth making a little effort.
Browne is also full of good sense. What better way could I find to construct this post than to offer some of his thoughts for your reflection:
'The religion of one seems madness unto another.'
And to some, any kind of religion is deeply suspicious.
'The greater part [of men] must be content to be as though they had not been: to be found in the register of God, not in the record of man.'
Think about that, o ye who yearn to be famous.
'To be ignorant of evils to come and forgetful of evils past is a merciful provision in nature.'
I recently met an old man in a gym (older than me, even). He told me that he had been sent by his doctor, but for sixteen hours a day he had to be linked to an oxygen tank to aid his breathing! 'It is lucky,' he said, 'that we don't know what the future holds for us.' Thus echoing Browne, who beat him to it by 360 years or so.
'But all was vanity, feeding the wind, and folly.'
This is said in reference to the pharaohs of Egypt trying to mummify themselves to last for ever, but it applies to much else. 'Feeding the wind, and folly' certainly rings a few bells with anyone who has had anything to do with publishing.
'Life is a pure flame, and we live by an invisible sun within us.'
'Happy are they... who deal so with men in this world that they are not afraid to meet them in the next.'
And so on. But there is no substitute for reading the original. You will probably do better to look for an old edition on abebooks than for a modern one on Amazon, either in the UK or the US. And if you would like to get a taste of the thing online, before buying, you can find a complete text here. Plus a great deal more.