Timaeus — Plato

The formation of blood : digestion. 503 originated. For the fire cuts the food and following the Timaeus. breath surges up within, fire and breath rising together and Timaeus. filling the veins by drawing up out of the belly and pouring into them the cut portions of the food ; and so the streams of food are kept flowing through the whole body in all animals.

And fresh cuttings from kindred substances, whether the fruits of the earth or herb of the field, which God planted to be our daily food, acquire all sorts of colours by their intermixture ; but red is the most pervading of them, being The red coicreated by the cutting action of fire and by the impression oi"" of blood ■' ^ , -^ ^ is due to the which it makes on a moist substance; and hence the liquid action of fire. which circulates in the body has a colour such as we have described.

The liquid itself we call blood, which nourishes I the flesh and the whole body, whence all parts are watered and empty places filled. Now the process of repletion and evacuation is effected The bodily after the manner of the universal motion by which all kin- p''°J=^^^^s of •' repletion and dred substances are drawn towards one another.

For the evacuation are external elements which surround us are always causing us attraction to consume away, and distributing and sending off like to like ; the particles of blood, too, which are divided and contained within the frame of the animal as in a sort of heaven, are compelled to imitate the motion of the universe. Each, therefore, of the divided parts within us, being carried to its kindred nature, replenishes the void.

When more is taken away than flows in, then we decay, and when less, we grow and increase. The frame of the entire creature when young has the when the triangles of each kind new, and may be compared to the ^°^J['^jhe keel of a vessel which is just off the stocks; they are locked triangles of firmly together and yet the whole mass is soft and delicate, ^^^pose^^ being freshly formed of marrow and nurtured on milk.

Now are new and when the triangles out of which meats and drinks are com- oJ°"com^e"the posed come in from without, and are comprehended in the trianpiesof body, being older and weaker than the triangles already \^J'^^'^^ there, the frame of the body gets the better of them and its they are ovcr- , , 1 1 • 1 J. come by them. newer tnangles cut them up, and so the animal grows great, being nourished by a multitude of similar particles. But when the roots of the triangles are loosened by having undergone many conflicts with many things in the course

p. 504

The causes of disease in the body.

Tiiuaeus. TiMAEUS.

Death takes place when the triangles of the marrow, becoming disunited, loosen the soul's bonds. A natural death is pleasant, a violent, painful.

Diseases of the body arise (i) when any of the four elements is out of place or there is too much or too little of them in any part;

and (ii) when blood, flesh, and sinews are produced in a wrong order.

of time, they are no longer able to cut or assimilate the food which enters, but are themselves easily divided by the bodies which come in from without. In this way every animal is overcome and decays, and this affection is called old age.

And at last, when the bonds by which the triangles of the marrow are united no longer hold, and are parted by the strain of existence, they in turn loosen the bonds of the soul, and she, obtaining a natural release, flies away with joy. For that which takes place according to nature is pleasant, but that which is contrary to nature is painful.

And thus death, if caused by disease or produced by wounds, is painful and violent ; but that sort of death which comes with old age and fulfils the debt of nature is the easiest of deaths, and is accompanied with pleasure rather than with pain. Now every one can see whence diseases arise.

There are four natures out of which the body is compacted, earth and 82 fire and water and air, and the unnatural excess or defect of these, or the change of any of them from its own natural place into another, or — since there are more kinds than one of fire and of the other elements — the assumption by any of these of a wrong kind, or any similar irregularity, produces disorders and diseases ; for when any of them is produced or changed in a manner contrary to nature, the parts which were previously cool grow warm, and those which were dry become moist, and the light become heavy, and the heavy light ; all sorts of changes occur.

For, as we affirm, a. thing can only remain the same with itself, whole and sound, when the same is added to it, or subtracted from it, in the same respect and in the same manner and in due proportion ; and whatever comes or goes away in violation of these laws causes all manner of changes and infinite diseases and corruptions.

Now there is a second class of structures which are also natural, and this affords a second opportunity of observing diseases to him who would understand them.

For whereas marrow and bone and flesh and sinews aje composed of the four elements, and the blood, though after another manner, is likewise formed out of them, most diseases originate in the way which I have described ; ])ut the worst of all owe their severity to the fact that the generation of these substances proceeds in a wrong order ; they are then destroyed. For the natural order is that the flesh