Book III chapter 10

These two at all events appear to be sources of movement: appetite and mind (if one may venture to regard imagination as a kind of thinking; for many men follow their imaginations contrary to knowledge, and in all animals other than man there is no thinking or calculation but only imagination).

Both of these then are capable of originating local movement, mind and appetite: (1) mind, that is, which calculates means to an end, i.e. mind practical (it differs from mind speculative¹ in the character of its end); while (2) appetite is in every form of it relative to an end: for that which is the object of appetite is the stimulant² of mind practical; and that which is last in the process of thinking is the beginning of the action. It follows that there is a justification³ for regarding these two as the sources of movement, i.e. appetite and practical thought; for the object of appetite starts a movement and as a result of that thought gives rise to movement, the object of appetite being it a source of stimulation⁴. So too when imagination originates movement, it necessarily involves appetite.

That which moves therefore is a single faculty⁵ and the faculty of appetite; for if there had been two sources of movement-mind and appetite-they would have produced movement in virtue⁶ of some common character. As it is, mind is never found producing movement without appetite (for wish is a form of appetite; and when movement is produced according to calculation it is also according to wish), but appetite can originate movement contrary to calculation, for desire is a form of appetite. Now mind is always right, but appetite and imagination may be either right or wrong. That is why, though in any case it is the object of appetite which originates movement, this object may be either the real or the apparent good. To produce movement the object must be more than this: it must be good that can be brought into being by action; and only what can be otherwise than as it is can thus be brought into being. That then such a power in the soul as has been described, i.e. that called appetite, originates movement is clear. Those who distinguish parts in the soul, if they distinguish and divide in accordance with differences of power, find themselves with a very large number of parts, a nutritive, a sensitive, an intellective, a deliberative, and now an appetitive part; for these are more different from one another than the faculties⁷ of desire and passion.

Since appetites run counter to one another, which happens when a principle of reason and a desire are contrary and is possible only in beings with a sense of time (for while mind bids us hold back because of what is future, desire is influenced by what is just at hand: a pleasant object which is just at hand presents itself as both pleasant and good, without condition in either case, because of want of foresight⁸ into what is farther away in time), it follows that while that which originates movement must be specifically one, viz. the faculty of appetite as such (or rather farthest back of all the object of that faculty; for it is it that itself remaining unmoved originates the movement by being apprehended⁹ in thought or imagination), the things that originate movement are numerically many.

All movement involves three factors, (1) that which originates the movement, (2) that by means of which it originates it, and (3) that which is moved. The expression ‘that which originates the movement’ is ambiguous: it may mean either (a) something which itself is unmoved or (b) that which at once moves and is moved. Here that which moves without itself being moved is the realizable good, that which at once moves and is moved is the faculty of appetite (for that which is influenced by appetite so far as it is actually so influenced is set in movement, and appetite in the sense of actual appetite is a kind of movement), while that which is in motion is the animal. The instrument which appetite employs to produce movement is no longer psychical¹⁰ but bodily: hence the examination of it falls within the province of the functions common to body and soul. To state the matter summarily at present, that which is the instrument in the production of movement is to be found where a beginning and an end coincide as e.g. in a ball and socket¹¹ joint¹²; for there the convex and the concave sides are respectively an end and a beginning (that is why while the one remains¹³ at rest, the other is moved): they are separate in definition but not separable spatially¹⁴. For everything is moved by pushing and pulling. Hence just as in the case of a wheel, so here there must be a point which remains at rest, and from that point the movement must originate.

To sum up, then, and repeat what I have said, inasmuch as an animal is capable of appetite it is capable of self-movement; it is not capable of appetite without possessing imagination; and all imagination is either (1) calculative or (2) sensitive. In the latter an animals, and not only man, partake.

1 speculative   

adj.思索性的，暝想性的，推理的

参考例句：

• Much of our information is speculative.我们的许多信息是带推测性的。
• The report is highly speculative and should be ignored.那个报道推测的成分很大，不应理会。

2 stimulant   

n.刺激物，兴奋剂

参考例句：

• It is used in medicine for its stimulant quality.由于它有兴奋剂的特性而被应用于医学。
• Musk is used for perfume and stimulant.麝香可以用作香料和兴奋剂。

3 justification   

n.正当的理由；辩解的理由

参考例句：

• There's no justification for dividing the company into smaller units. 没有理由把公司划分成小单位。
• In the young there is a justification for this feeling. 在年轻人中有这种感觉是有理由的。

4 stimulation   

n.刺激，激励，鼓舞

参考例句：

• The playgroup provides plenty of stimulation for the children.幼儿游戏组给孩子很多启发。
• You don't get any intellectual stimulation in this job.你不能从这份工作中获得任何智力启发。

5 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。

6 virtue   

n.德行，美德；贞操；优点；功效，效力

参考例句：

• He was considered to be a paragon of virtue.他被认为是品德尽善尽美的典范。
• You need to decorate your mind with virtue.你应该用德行美化心灵。

7 faculties   

n.能力( faculty的名词复数 )；全体教职员；技巧；院

参考例句：

• Although he's ninety, his mental faculties remain unimpaired. 他虽年届九旬，但头脑仍然清晰。
• All your faculties have come into play in your work. 在你的工作中，你的全部才能已起到了作用。 来自《简明英汉词典》

8 foresight   

n.先见之明，深谋远虑

参考例句：

• The failure is the result of our lack of foresight.这次失败是由于我们缺乏远虑而造成的。
• It required a statesman's foresight and sagacity to make the decision.作出这个决定需要政治家的远见卓识。

9 apprehended   

逮捕，拘押( apprehend的过去式和过去分词 )； 理解

参考例句：

• She apprehended the complicated law very quickly. 她很快理解了复杂的法律。
• The police apprehended the criminal. 警察逮捕了罪犯。

10 psychical   

adj.有关特异功能现象的；有关特异功能官能的；灵魂的；心灵的

参考例句：

• Conclusion: The Liuhe-lottery does harm to people, s psychical health and should be for bidden. 结论：“六合彩”赌博有害人们心理卫生，应予以严禁。 来自互联网

11 socket   

n.窝，穴，孔，插座，插口

参考例句：

• He put the electric plug into the socket.他把电插头插入插座。
• The battery charger plugs into any mains socket.这个电池充电器可以插入任何类型的电源插座。

12 joint   

adj.联合的，共同的；n.关节，接合处；v.连接，贴合

参考例句：

• I had a bad fall,which put my shoulder out of joint.我重重地摔了一跤，肩膀脫臼了。
• We wrote a letter in joint names.我们联名写了封信。

13 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。

14 spatially   

空间地，存在于空间地

参考例句：

• A well-defined array of stable fringes results and the field is spatially coherent. 结果得到一组完全确定的稳定条纹，而光场是空间相干的。
• The units are collaged together by a serial tectonic spatially and temporally. 这些构造单元是由构造原因，依一定的时空序列拼贴在一起的。