On the nature of things (books 1 - 3)   

Of those about him standing with wet cheeks
Who vainly call him back to light and life.
Wherefore mind too, confess we must, dissolves,
Seeing, indeed, contagions of disease
Enter into the same. Again, O why,
When the strong wine has entered into man,
And its diffused fire gone round the veins,
Why follows then a heaviness of limbs,
A tangle of the legs as round he reels,
A stuttering tongue, an intellect besoaked,
Eyes all aswim, and hiccups, shouts, and brawls
And whatso else is of that ilk?- Why this?-
If not that violent and impetuous wine
Is wont to confound the soul within the body?
But whatso can confounded be and balked,
Gives proof, that if a hardier cause got in,
'Twould hap that it would perish then, bereaved
Of any life thereafter. And, moreover,
Often will some one in a sudden fit,
As if by stroke of lightning, tumble down
Before our eyes, and sputter foam, and grunt,
Blither, and twist about with sinews taut,
Gasp up in starts, and weary out his limbs
With tossing round. No marvel, since distract
Through frame by violence of disease.

Confounds, he foams, as if to vomit soul,
As on the salt sea boil the billows round
Under the master might of winds. And now
A groan's forced out, because his limbs are griped
But, in the main, because the seeds of voice
Are driven forth and carried in a mass
Outwards by mouth, where they are wont to go,
And have a builded highway. He becomes
Mere fool, since energy of mind and soul
Confounded is, and, as I've shown, to-riven,
Asunder thrown, and torn to pieces all
By the same venom. But, again, where cause
Of that disease has faced about, and back
Retreats sharp poison of corrupted frame
Into its shadowy lairs, the man at first
Arises reeling, and gradually comes back
To all his senses and recovers soul.
Thus, since within the body itself of man
The mind and soul are by such great diseases
Shaken, so miserably in labour distraught,
Why, then, believe that in the open air,
Without a body, they can pass their life,
Immortal, battling with the master winds?
And, since we mark the mind itself is cured,
Like the sick body, and restored can be
By medicine, this is forewarning to
That mortal lives the mind. For proper it is
That whosoe'er begins and undertakes
To alter the mind, or meditates to change
Any another nature soever, should add
New parts, or readjust the order given,
Or from the sum remove at least a bit.
But what's immortal willeth for itself
Its parts be nor increased, nor rearranged,
Nor any bit soever flow away:
For change of anything from out its bounds
Means instant death of that which was before.
Ergo, the mind, whether in sickness fallen,