On the Nature of the Universe (Oxford World’s Classics) Page 18

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  Follows behind, fills every pore, blockades

  The channels of the eyes, so that no images

  Thrown off from things in any way can move them.

  And when we see the square towers of a city

  From far away, they often appear to be round.

  This is because every angle when seen at a distance

  355

  Is blurred, or rather is not seen at all.

  Its flow is lost, it does not strike our eyes,

  And the air, while the images travel so far through it,

  Inflicts many blows upon them and blunts them.

  So when every angle has escaped our vision

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  The stone structures appear as though turned on a lathe,

  Not like things really round that are seen close to,

  But in a shadowy way they mimic them.

  Our shadow also appears to move in the sun,

  To follow our footsteps, imitate our gestures,

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  If you can conceive that air without light can walk

  And follow the movements and gestures of men;

  For what we are accustomed to call shadow

  Can be nothing else than air deprived of light.

  Doubtless because the air in certain places

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  One after another is deprived of the sun’s light

  Wherever in our movements we obstruct it,

  And the point which we have left is filled again;

  That is why the successive shadows of our body

  Seem to be the same shadow always following us.

  For always new rays of light are pouring out

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  And the first are consumed, like wood thrown into a flame.

  Thus easily the earth is robbed of light

  And is replenished as it washes away

  The stain of the black shadows darkening it.

  And here we do not concede in any way

  That the eyes are deluded. For their task it is

  To see in what place light is, and where shadow;

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  But whether one light is the same as another,

  Whether the shadow that was here is now moving there,

  Or rather what happens is what I have just described,

  That the mind’s reasoning power must discern.

  Eyes cannot understand the nature of things.

  385

  Do not then blame the eyes for this fault of the mind.

  A ship we sail in moves while it seems to stand still.

  A ship at anchor seems to be passing by,

  And hills and plains appear to fly astern

  When we drive our vessel past them with flying sails.

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  The stars in all the vaults of heaven seem fixed

  And still, yet all are in constant motion,

  Since to their distant setting they return

  When with bright bodies they have crossed the sky.

  The sun and moon likewise seem to stand still

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  In their places, though the facts show that they move.

  In the midst of the ocean mountains rise far off,

  Between them lies a channel for a fleet,

  And yet they seem to form a single island.

  When children spinning round have come to a stop

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  They seem to see halls and pillars whirling round

  So vividly that they can scarce believe

  That the whole roof will not fall in on them.

  And when with flickering fires nature begins

  To lift her red glow on high, above the hills,

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  The glowing sun seems to be close upon them

  And touching them with its own heat and fire.

  Yet scarce two thousand bowshots are they distant

  Or even five hundred throws of a javelin;

  But far between them and the sun there lie

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  Enormous tracts of ocean spread below

  Vast regions of the sky, and many thousands

  Of lands lie in between where many men

  And varied nations dwell and tribes of beasts.

  A puddle no more than a finger deep

  Lying between stones on a paved highway

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  Gives a view downwards below the earth as far

  As the expanse of sky that yawns above,

  So that you seem to look down upon the clouds

  And see the heavenly bodies wonderfully

  Deep-buried in a heaven below the earth.

  Again, when in midstream our lively horse

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  Stands fast, and we look down upon the waves

  Of the river flowing rapidly, a force

  Seems to be carrying his body sideways

  And to push it violently against the stream,

  And wherever we turn our eyes, everything seems

  To be rushing and flowing in a similar way.

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  A colonnade of equal width throughout

  Supported by pillars of equal height

  If you look down its whole length from one end

  It gradually takes the outlines of a cone

  Quite joining roof to floor and right to left

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  Until the invisible apex of the cone is reached.

  At sea, to sailors from the waves the sun

  Appears to rise, then set and hide its light in them.

  This is because they see only sea and sky,

  Lest you should readily believe the senses

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  Are everywhere confused and undermined.

  To landsmen ignorant of the sea a ship

  In harbour seems to struggle against the waves

  Maimed, its poop broken. For whatever part

  Of the oar is raised above the sea is straight

  And the rudders above are straight; but the parts submerged

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  Below the water appear all broken back

  And wrenched and turned flat upwards and so bent

  Right back almost to float upon the surface.

  And when at night the winds drive scattered clouds

  Across the sky, the shining stars appear

  To glide against the clouds and pass above them

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  On a way far different from their actual course.

  And if you place a hand below one eye

  And press it, then a new sensation comes.

  Everything we see is doubled by our vision.

  Two lights of lamps a-flowering with flames,

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  Two sets of furniture all through the house,

  And men with double faces and two bodies.

  When in sweet slumber sleep has bound our limbs

  And in deep quiet all the body lies

  Yet we seem then to ourselves to be awake

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  And move our limbs, and in the night’s blind dark

  We think we see the sun and light of day,

  That in our narrow room we pass in turn

  Over sky and sea, rivers and mountains;

  We see ourselves walking across wide plains.

  We hear sounds, though the stern silence of night

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  Reigns everywhere; we speak, but still are silent.

  And many marvels in this way we see

  Which seek as it were to break the credit of our senses,

  But all in vain, since the most part of them

  Deceive because of notions of the mind

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  Which we ourselves bring to them, so that things

  Seem so be seen which senses have not seen.

  For nothing is more difficult than to distinguish

  And separate plain things from doubtful things

  Which all at once are added by the mind.

  Now here’s another thing: if someone thinks
/>
  That nothing is known, he does not even know

  Whether that can be known, since he declares

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  That he knows nothing. Therefore I will spare

  To argue a case against a man like this

  Who has put his head where his feet ought to be.

  And yet, if I were to grant that he does know, then

  I ask him this: since you could see no truth

  In anything before, how do you know

  What it is to know, and what again not to know?

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  What gave you the idea of true and false,

  What proves to you that there’s a difference,

  That the doubtful and the certain are not the same?

  You will find that it is from the senses

  In the first place that the concept of truth has come,

  And that the senses cannot be refuted.

  For some standard must be found of greater credit

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  Able of itself to refute false things with true.

  And what can be held to tell the truth more clearly

  Than the senses? or shall reasoning derived

  From false senses prevail against those senses

  Being itself wholly derived from them?

  Unless they are true, all reasoning is false.

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  Will the ear be able to convict the eye?

  Or the touch the ear? Or taste refute the touch,

  Or nose confound it or eye discredit it?

  Not so, I think. For each has its own force

  And separate power, so it needs must be

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  That softness and cold or heat and colour each

  Is separately perceived and separately

  We see whatever is involved in colour.

  The taste in our mouth has its separate power, and smells

  Have separate birth, and sounds. So it must be

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  That one sense never can refute another

  Nor can they possibly convict themselves

  Since each must always equally be trusted.

  Accordingly whatever at any time

  Has seemed to the senses to be true, is true.

  And if reason cannot explain the cause

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  Why objects seen as square close to at a distance

  Seem round, yet it is better that a man

  Lacking reason should give a faulty explanation

  Than to let slip from your hands in any way

  Your grip upon the obvious, and break

  The trust upon which all depends, and tear up

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  All the foundations on which life is built.

  For not only would all reason come to ruin,

  Life itself also would at once collapse,

  Unless you dare to place trust in your senses,

  Avoiding precipices and such things

  As must be shunned, and follow the contrary.

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  Believe me, all that array of words is vain

  That has been massed and deployed against the senses.

  Lastly, in a building, if the ruler is crooked

  And the square is faulty and misses the straight line

  And the level is even slightly unbalanced,

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  The whole house then will of necessity

  Be wrongly constructed and be falling over,

  Warped, sloping, leaning forward, leaning back,

  All out of proportion, so that some parts seem

  Ready to collapse, and the whole destined to fall,

  A victim to the first false measurements.

  So your reasoning about things must be false and warped

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  Whenever it is based upon false senses.

  And now I have no stony path to tread

  In showing how the other senses work.

  In the first place, every sound and voice is heard

  When it has crept into the ears, and then

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  Made impact with its body upon the senses.

  For we must confess that voice and sound also

  Have bodies, since they strike upon the senses.

  Besides, the voice often scrapes the throat. A shout

  Roughens the windpipe on its outward course.

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  For when the voice’s atoms massed together

  Make their way out through the narrow passage,

  As the mouth is filled the gateway is scraped.

  There is no doubt therefore that words and voices

  Consist of bodily elements, since they can hurt.

  You see also how much the body is worn,

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  How much is drawn from man’s very thews and sinews

  By a speech that lasts from the first gleam of dawn

  To the black shades of night, especially

  If the words are shouted, at the top of the voice.

  Therefore the voice must be made of bodily stuff,

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  Since much speaking diminishes the body.

  The roughness of the voice moreover comes

  From the roughness of its atoms, and smoothness from smooth.

  The atoms that enter the ear are not of the same shape

  When the horn bellows with deep and hollow roar

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  And the land re-echoes with its barbarous boom

  As when swans from the glens of Helicon

  With liquid voice uplift their mournful plaint.

  When therefore from deep within our body

  We force the voices out and send them forth

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  Straight through the mouth, the quickly moving tongue,

  The cunning fashioner of words, joints them

  And moulds them, and the shaping of the lips

  Plays its due part in giving form to them.

  When there is no great distance for the voice

  To run, it follows that the words themselves

  Are clearly heard, each separate syllable.

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  For the sound keeps its shape and keeps its form.

  But if the space between is unduly long,

  Words passing through much air must be confused

  And the voice distorted as it flies through the air.

  And that is why, though you can hear the sound,

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  You cannot grasp the meaning of the words,

  The voice is so obstructed and confused.

  Often one voice can penetrate the ears

  Of a whole crowd, when uttered by a cryer.

  Therefore one voice is suddenly dispersed

  Into many voices, since it divides itself

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  Into separate ears, stamping on them

  The form of the word and its distinctive sound.

  But those voices that do not strike the ear

  Are carried past, and lost, and all in vain

  Are scattered through the air and perish there.

  Some, hitting solid objects, give back a sound

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  And at times delude with the image of a word.

  And when you clearly see this You’ll be able

  To give the reason to yourself and others

  Why cliffs and rocks standing in lonely places

  Give back the sounds in the same shape and order

  When straying comrades in thick mountain country

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  We seek and with loud voices call to them.

  Six times or even seven I have heard come back

  One voice, so skilfully did hill from hill

  Repeat the words and throw them back again.

  Nymphs and goat-footed satyrs haunt these places,

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  So country-folk make out; and fauns they say

  Are there as well, when their night-wandering noises

  And merry pranks break the deep silences;

  And there are s
ounds of strings; and sweet laments

  The flute pours out pressed by a player’s fingers;

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  And everywhere the farm-folk listen, while Pan

  Shaking the pine-leaves from his half-wild head

  Runs his curved lips along the hollow reeds

  And pipes all day his woodland melody.

  And other signs and wonders they relate

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  Lest they be thought to live in haunts so wild

  That even the gods have left them; or maybe

  They have some other reason, for mankind

  Is greedy aye for things that please the ear.

  Well now, here’s something you can well believe:

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  That voices can come and impact on the ears

  From places through which eyes can never see.

  We hear a conversation through closed doors

  Doubtless because the voice can travel safe

  Through tortuous paths, while images refuse.

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  For they are split apart unless they swim

  Through straight passages, such as glass contains,

  Through which all things that can be seen can fly.

  The voice is spread about in all directions

  Since voices beget voices, when one voice

  Once spoken has sprung apart into many, as fires

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  Lit by a spark break out into many fires.

  So places are filled with voices, and though withdrawn

  And hidden from sight they are stirred and boil with sound.

  But images all travel in straight paths

  When once they have been sent out. And therefore no one

  610

  Can see beyond a wall, though he hear voices through it.

  Yet the voice itself passing through the walls of a house

  Comes blunted and confused into the ears

  And we seem to hear a sound rather than words.

  The tongue now, and the palate, which give us taste

  615

  Need no more work of reasoning to explain.

  In the first place we sense flavour in the mouth

  When we press it out in chewing food, as a sponge

  When full of water is pressed and begins to dry.

  Next, what we press out is distributed

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  Abroad through all the passages of the palate

  And winding channels of the porous tongue.

  Therefore when bodies of the oozing juice

  Are smooth, they sweetly touch and sweetly stroke

  All the wet trickling regions round the tongue.

  But contrariwise they prick the sense and tear it,

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  Being pressed out, the more they are filled with roughness.

  The pleasure of flavour stops short at the palate.

  When it has dropped down through the throat no pleasure

  Is given while it disperses through our limbs.

  It matters not what food is given the body