Book III chapter 12

The nutritive soul then must be possessed¹ by everything that is alive, and every such thing is endowed with soul from its birth to its death. For what has been born must grow, reach maturity², and decay-all of which are impossible without nutrition. Therefore the nutritive faculty³ must be found in everything that grows and decays.

But sensation need not be found in all things that live. For it is impossible for touch to belong either (1) to those whose body is uncompounded or (2) to those which are incapable⁴ of taking in the forms without their matter.

But animals must be endowed with sensation, since Nature does nothing in vain. For all things that exist by Nature are means to an end, or will be concomitants of means to an end. Every body capable of forward movement would, if unendowed with sensation, perish and fail to reach its end, which is the aim of Nature; for how could it obtain nutriment? Stationary⁵ living things, it is true, have as their nutriment that from which they have arisen; but it is not possible that a body which is not stationary but produced by generation should have a soul and a discerning mind without also having sensation. (Nor yet even if it were not produced by generation. Why should it not have sensation? Because it were better so either for the body or for the soul? But clearly it would not be better for either: the absence of sensation will not enable the one to think better or the other to exist better.) Therefore no body which is not stationary has soul without sensation.

But if a body has sensation, it must be either simple or compound. And simple it cannot be; for then it could not have touch, which is indispensable. This is clear from what follows. An animal is a body with soul in it: every body is tangible⁶, i.e. perceptible by touch; hence necessarily, if an animal is to survive, its body must have tactual sensation. All the other senses, e.g. smell, sight, hearing, apprehend⁷ through media; but where there is immediate⁸ contact the animal, if it has no sensation, will be unable to avoid some things and take others, and so will find it impossible to survive. That is why taste also is a sort of touch; it is relative to nutriment, which is just tangible body; whereas sound, colour, and odour are innutritious, and further neither grow nor decay. Hence it is that taste also must be a sort of touch, because it is the sense for what is tangible and nutritious⁹.

Both these senses, then, are indispensable to the animal, and it is clear that without touch it is impossible for an animal to be. All the other senses subserve well-being¹⁰ and for that very reason belong not to any and every kind of animal, but only to some, e.g. those capable of forward movement must have them; for, if they are to survive, they must perceive not only by immediate contact but also at a distance from the object. This will be possible if they can perceive through a medium, the medium being affected¹¹ and moved by the perceptible object, and the animal by the medium. just as that which produces local movement causes a change extending to a certain point, and that which gave an impulse causes another to produce a new impulse so that the movement traverses a medium the first mover impelling¹² without being impelled¹³, the last moved being impelled without impelling, while the medium (or media, for there are many) is both-so is it also in the case of alteration¹⁴, except that the agent produces produces it without the patient’s changing its place. Thus if an object is dipped into wax, the movement goes on until submersion has taken place, and in stone it goes no distance at all, while in water the disturbance¹⁵ goes far beyond the object dipped: in air the disturbance is propagated farthest of all, the air acting¹⁶ and being acted upon, so long as it maintains an unbroken unity¹⁷. That is why in the case of reflection it is better, instead of saying that the sight issues from the eye and is reflected, to say that the air, so long as it remains¹⁸ one, is affected by the shape and colour. On a smooth surface the air possesses unity; hence it is that it in turn sets the sight in motion, just as if the impression on the wax were transmitted as far as the wax extends.

1 possessed   

adj.疯狂的；拥有的，占有的

参考例句：

• He flew out of the room like a man possessed.他像着了魔似地猛然冲出房门。
• He behaved like someone possessed.他行为举止像是魔怔了。

2 maturity   

n.成熟；完成；(支票、债券等)到期

参考例句：

• These plants ought to reach maturity after five years.这些植物五年后就该长成了。
• This is the period at which the body attains maturity.这是身体发育成熟的时期。

3 faculty   

n.才能；学院，系；(学院或系的)全体教学人员

参考例句：

• He has a great faculty for learning foreign languages.他有学习外语的天赋。
• He has the faculty of saying the right thing at the right time.他有在恰当的时候说恰当的话的才智。

4 incapable   

adj.无能力的，不能做某事的

参考例句：

• He would be incapable of committing such a cruel deed.他不会做出这么残忍的事。
• Computers are incapable of creative thought.计算机不会创造性地思维。

5 stationary   

adj.固定的，静止不动的

参考例句：

• A stationary object is easy to be aimed at.一个静止不动的物体是容易瞄准的。
• Wait until the bus is stationary before you get off.你要等公共汽车停稳了再下车。

6 tangible   

adj.有形的，可触摸的，确凿的，实际的

参考例句：

• The policy has not yet brought any tangible benefits.这项政策还没有带来任何实质性的好处。
• There is no tangible proof.没有确凿的证据。

7 apprehend   

vt.理解，领悟，逮捕，拘捕，忧虑

参考例句：

• I apprehend no worsening of the situation.我不担心局势会恶化。
• Police have not apprehended her killer.警察还未抓获谋杀她的凶手。

8 immediate   

adj.立即的；直接的，最接近的；紧靠的

参考例句：

• His immediate neighbours felt it their duty to call.他的近邻认为他们有责任去拜访。
• We declared ourselves for the immediate convocation of the meeting.我们主张立即召开这个会议。

9 nutritious   

adj.有营养的，营养价值高的

参考例句：

• Fresh vegetables are very nutritious.新鲜蔬菜富于营养。
• Hummingbirds have discovered that nectar and pollen are very nutritious.蜂鸟发现花蜜和花粉是很有营养的。

10 well-being   

n.安康，安乐，幸福

参考例句：

• He always has the well-being of the masses at heart.他总是把群众的疾苦挂在心上。
• My concern for their well-being was misunderstood as interference.我关心他们的幸福，却被误解为多管闲事。

11 affected   

adj.不自然的，假装的

参考例句：

• She showed an affected interest in our subject.她假装对我们的课题感到兴趣。
• His manners are affected.他的态度不自然。

12 impelling   

adj.迫使性的，强有力的v.推动、推进或敦促某人做某事( impel的现在分词 )

参考例句：

• Impelling-binding mechanism is the micro foundation of venture capital operation. 激励约束机制是创业投资运作的微观基础。 来自互联网
• Impelling supervision is necessary measure of administrative ethic construction. 强有力的监督是行政伦理建设的重要保证。 来自互联网

13 impelled   

v.推动、推进或敦促某人做某事( impel的过去式和过去分词 )

参考例句：

• He felt impelled to investigate further. 他觉得有必要作进一步调查。
• I feel impelled to express grave doubts about the project. 我觉得不得不对这项计划深表怀疑。 来自《简明英汉词典》

14 alteration   

n.变更，改变；蚀变

参考例句：

• The shirt needs alteration.这件衬衣需要改一改。
• He easily perceived there was an alteration in my countenance.他立刻看出我的脸色和往常有些不同。

15 disturbance   

n.动乱，骚动；打扰，干扰；(身心)失调

参考例句：

• He is suffering an emotional disturbance.他的情绪受到了困扰。
• You can work in here without any disturbance.在这儿你可不受任何干扰地工作。

16 acting   

n.演戏，行为，假装；adj.代理的，临时的，演出用的

参考例句：

• Ignore her,she's just acting.别理她，她只是假装的。
• During the seventies,her acting career was in eclipse.在七十年代，她的表演生涯黯然失色。

17 unity   

n.团结，联合，统一；和睦，协调

参考例句：

• When we speak of unity,we do not mean unprincipled peace.所谓团结，并非一团和气。
• We must strengthen our unity in the face of powerful enemies.大敌当前，我们必须加强团结。

18 remains   

n.剩余物，残留物；遗体，遗迹

参考例句：

• He ate the remains of food hungrily.他狼吞虎咽地吃剩余的食物。
• The remains of the meal were fed to the dog.残羹剩饭喂狗了。