Chapter 2

But the point of rest in the animal is still quite ineffectual unless there be something without which is absolutely at rest and immovable. Now it is worth while to pause and consider what has been said, for it involves a speculation¹ which extends² beyond animals even to the motion³ and march of the universe. For just as there must be something immovable within the animal, if it is to be moved, so even more must there be without it something immovable, by supporting itself upon which that which is moved moves. For were that something always to give way (as it does for mice walking in grain or persons walking in sand) advance would be impossible, and neither would there be any walking unless the ground were to remain still, nor any flying or swimming were not the air and the sea to resist. And this which resists must needs be different from what is moved, the whole of it from the whole of that, and what is thus immovable must be no part of what is moved; otherwise there will be no movement. Evidence of this lies in the problem why it is that a man easily moves a boat from outside, if he push with a pole, putting it against the mast⁴ or some other part, but if he tried to do this when in the boat itself he would never move it, no not giant Tityus himself nor Boreas blowing from inside the ship, if he really were blowing in the way painters represent him; for they paint him sending the breath out from the boat. For whether one blew gently or so stoutly⁵ as to make a very great wind, and whether what were thrown or pushed were wind or something else, it is necessary in the first place to be supported upon one of one’s own members which is at rest and so to push, and in the second place for this member, either itself, or that of which it is a part, to remain at rest, fixing itself against something external⁶ to itself. Now the man who is himself in the boat, if he pushes, fixing himself against the boat, very naturally does not move the boat, because what he pushes against should properly remain at rest. Now what he is trying to move, and what he is fixing himself against is in his case the same. If, however, he pushes or pulls from outside he does move it, for the ground is no part of the boat.

1 speculation   

n.思索，沉思；猜测；投机

参考例句：

• Her mind is occupied with speculation.她的头脑忙于思考。
• There is widespread speculation that he is going to resign.人们普遍推测他要辞职。

2 extends   

v.（空间、时间等）延伸，延续( extend的第三人称单数 )；伸展；给予；延长

参考例句：

• This country extends its power and influence into neighbouring countries. 这个国家将其势力与影响扩大至邻国。 来自《简明英汉词典》
• His domain extends for 20 miles in every direction. 方圆20英里之内都是他的地产。 来自《简明英汉词典》

3 motion   

n.打手势，示意，移动，动作，提议，大便；v.运动，向...打手势，示意

参考例句：

• She could feel the rolling motion of the ship under her feet.她能感觉到脚下船在晃动。
• Don't open the door while the train is in motion.列车运行时，请勿打开车门。

4 mast   

n.船桅，桅杆，旗杆，天线杆

参考例句：

• Flags are flying at half-mast across China.全中国将半旗。
• The sails were flapping against the mast.帆拍打着桅杆。

5 stoutly   

adv.牢固地，粗壮的

参考例句：

• He stoutly denied his guilt.他断然否认自己有罪。
• Burgess was taxed with this and stoutly denied it.伯杰斯为此受到了责难，但是他自己坚决否认有这回事。

6 external   

adj.外部的，外面的，外来的；与外国有关的

参考例句：

• External causes become operative through internal causes.外因通过内因而起作用。
• The external features of the building are very attractive.这座建筑物的外观是很吸引人的。