Passages from Leonardo da Vinci's notebooks

The knowledge of past times and of the places on the earth is both an ornament and nutriment to the human mind.

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Avoid studies of which the result dies with the worker.

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Learning acquired in youth arrests the evil of old age; and if you understand that old age has wisdom for its food, you will so conduct yourself in youth that your old age will not lack for nourishment.

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As a day well spent procures a happy sleep, so a life well employed procures a happy death.

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Just as food eaten without caring for it is turned into loathsome nourishment, so study without a taste for it spoils memory, by retaining nothing which it has taken in.

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Why does the eye see a thing more clearly in dreams than with the imagination being awake?

With music, feasting and fun

W.H. Auden, Loneliness:

Gate-crashing ghost, aggressive
invisible visitor,
tactless gooseberry, spoiling
my tête-à-tête with myself,
blackmailing brute, behaving
as if the house were your own,
so viciously pursuing
your victim from room to room,
monotonously nagging,
ungenerous jabberer,
dirty devil, befouling
fair fancies, making the mind
a quagmire of disquiet,
weakening my will to work,
shadow without shape or sex,
excluding consolation,
blotting out Nature's beauties,
grey mist between me and God,
pestilent problem that won't
be put on the black-burner,
hard it is to endure you.

Routine is the one technique
I know of that enables
your host to ignore you now:
while typing business letters,
laying the table for one,
gobbling a thoughtless luncheon,
I briefly forget you're there,
but am safe from your haunting
only when soundly asleep.

History counsels patience:
tyrants come, like plagues, but none
can rule the roost for ever.
Indeed, your totter is near,
your days numbered: to-morrow
Chester, my chum, will return.
Then you'll be through: in no time
he'll throw you out neck-and-crop.
We'll merry-make your cadence
with music, feasting and fun.