芝诺是古希腊一个极善于诡辩的哲学家。他的一个众人皆知的“阿基里斯永远追不上乌龟”的诡辩是这样的：阿基里斯是古希腊神话中善跑的英雄。假设乌龟先爬一段路然后阿基里斯去追它。芝诺认为阿基里斯永远追不上乌龟。因为前者在追上后者之前必须首先达到后者的出发点，可是，这时后者又向前爬了一段路了。于是前者又必须赶上这段路，可是这时后者又向前爬了。由于阿基里斯和乌龟之间的距离可依次分成无数小段，因此阿基里斯虽然越追越近，但永远追不上乌龟。
当然，这个结论在实践上是错误的，但奇怪的是这一论证在逻辑上却没有任何毛病。
在古希腊，还有一更妙的诡辩是这样的：1粒谷子落地时没有响声，两粒谷子落地时也没有响声，3粒谷子落地时还是没有响声……以此类推，1整袋谷子落地时也不会有响声。这同样是实践上错，逻辑上对。
对于诡辩怎么看，人们往往习惯于从实践角度去评价它，总是根据事实去说它是错的，这种评价其实是没有真正理解那些古老诡辩家的意图。那些诡辩家自己也知道这些诡辩在实践上是错误的，他们也并不真的想否认事实，谁也没有这么傻，真正傻的是那些认为诡辩家是犯傻的人。那些人傻就傻在不去想一想诡辩到底说明了什么问题。其实，“实践上错，逻辑上对”这一结果是为了说明，思想的情况和事实的情况是不同的，思想中的真理和事实上的真理是不同的真理，这两种真理分别有着不同的用处。例如，逻辑定理与事实就常常不一致。有一条逻辑定理说的是“随便一句假话都能推出任何一句话”，这听上去十分荒唐。结果真的有人就要英国大哲学家罗素证明从“2＋2=5”推出“罗素是教皇”。深邃无比的罗素做出了如下的证明：假定2＋2=5；等式的两边各减去2，得出2=3；易位得3=2；两边各减去1，得出2=1；教皇与罗素是两个人，但既然2=1，教皇与罗素就是1个人，所以罗素是教皇。
这个结论，有人说是笑话，如果是这样，应当说是一个很深刻的笑话。由此，的确可以悟出，思想和事实是两回事，理解这一点至关重要。实际上这并不很难理解，我们在数学中讲到的点、线、面、平行线、三角形、圆形等等在事实上是不存在的，它们只是思想中的理想化的东西。思想与事实的联系只是表现为思想可以应用到事实中去。前面讲到的那两个诡辩只是给错误想法敲敲警钟，除此之外并没有什么用处，因为它们的确很荒谬。
有哲理的英文故事
推荐几个经典的英语小故事，边看故事边学英语。
A man was going to the house of some rich person. As he went along the road, he saw a box of good apples at the side of the road. He said, I do not want to eat those apples; for the rich man will give me much food; he will give me very nice food to eat. Then he took the apples and threw them away into the dust.
He went on and came to a river. The river had become very big; so he could not go over it. He waited for some time; then he said, I cannot go to the rich man's house today, for I cannot get over the river.
He began to go home. He had eaten no food that day. He began to want food. He came to the apples, and he was glad to take them out of the dust and eat them.
Do not throw good things away; you may be glad to have them at some other time.
【译文】
一个人正朝着一个富人的房子走去，当他沿着路走时，在路的一边他发现一箱好苹果，他说：“我不打算吃那些苹果，因为富人会给我更多的食物，他会给我很好吃的东西。”然后他拿起苹果，一把扔到土里去。
他继续走，来到河边，河涨水了，因此，他到不了河对岸，他等了一会儿，然后他说：“今天我去不了富人家了，因为我不能渡过河。”
他开始回家，那天他没有吃东西。他就开始去找吃的，他找到苹果，很高兴地把它们从尘土中翻出来吃了。
不要把好东西扔掉，换个时候你会觉得它们大有用处。
The Old Cat
An old woman had a cat. The cat was very old; she could not run quickly, and she could not bite, because she was so old. One day the old cat saw a mouse; she jumped and caught the mouse. But she could not bite it; so the mouse got out of her mouth and ran away, because the cat could not bite it.
Then the old woman became very angry because the cat had not killed the mouse. She began to hit the cat. The cat said, Do not hit your old servant. I have worked for you for many years, and I would work for you still, but I am too old. Do not be unkind to the old, but remember what good work the old did when they were young.
【译文】
老猫
一位老妇有只猫，这只猫很老，它跑不快了，也咬不了东西，因为它年纪太大了。一天，老猫发现一只老鼠，它跳过去抓这只老鼠，然而，它咬不住这只老鼠。因此，老鼠从它的嘴边溜掉了，因为老猫咬不了它。
于是，老妇很生气，因为老猫没有把老鼠咬死。她开始打这只猫，猫说：“不要打你的老仆人，我已经为你服务了很多年，而且还愿意为你效劳，但是，我实在太老了，对年纪大的不要这么无情，要记住老年人在年青时所做过的有益的事情。”
Teacher:Why are you late for school every morning?
Tom:Every time I come to the corner,a sign says,School-Go slow.
老师:为什么你每天早晨都迟到?
汤姆:每当我经过学校的拐角处,就看见一个牌子上写着学校----慢行.
A Good Boy
Little Robert asked his mother for two cents. What did you do with the money I gave you yesterday?
I gave it to a poor old woman, he answered.
You're a good boy, said the mother proudly. Here are two cents more. But why are you so interested in the old woman?
She is the one who sells the candy.
好孩子
小罗伯特向妈妈要两分钱。
“昨天给你的钱干什么了？”
“我给了一个可怜的老太婆，”他回答说。 “你真是个好孩子，”妈妈骄傲地说。“再给你两分钱。可你为什么对那位老太太那么感兴趣呢？”
“她是个卖糖果的。”
Drunk
One day, a father and his little son were going home. At this age, the boy was interested in all kinds of things and was always asking questions. Now, he asked, What's the meaning of the word 'Drunk', dad? Well, my son, his father replied, look, there are standing two policemen. If I regard the two policemen as four then I am drunk.
But, dad, the boy said, there's only ONE policeman!
醉酒
一天，父亲与小儿子一道回家。这个孩子正处于那种对什么事都很感兴趣的年龄，老是有提不完的问题。他向父亲发问道：“爸爸，‘醉’字是什么意思？” “唔，孩子，”父亲回答说，“你瞧那儿站着两个警察。如果我把他们看成了四个，那么我就算醉了。” “可是，爸爸， ”孩子说，“那儿只有一个警察呀！”
The City Mouse and the Country Mouse
Once there were two mice. They were friends. One mouse lived in the country; the other mouse lived in the city. After many years the Country mouse saw the City mouse; he said, Do come and see me at my house in the country. So the City mouse went. The City mouse said, This food is not good, and your house is not good. Why do you live in a hole in the field? You should come and live in the city. You would live in a nice house made of stone. You would have nice food to eat. You must come and see me at my house in the city.
The Country mouse went to the house of the City mouse. It was a very good house. Nice food was set ready for them to eat. But just as they began to eat they heard a great noise. The City mouse cried, Run! Run! The cat is coming! They ran away quickly and hid.
After some time they came out. When they came out, the Country mouse said, I do not like living in the city. I like living in my hole in the field. For it is nicer to be poor and happy, than to be rich and afraid.
【译文】
城里老鼠和乡下老鼠
从前，有两只老鼠，它们是好朋友。一只老鼠居住在乡村，另一只住在城里。很多年以后，乡下老鼠碰到城里老鼠，它说：“你一定要来我乡下的家看看。”于是，城里老鼠就去了。乡下老鼠领着它到了一块田地上它自己的家里。它把所有最精美食物都找出来给城里老鼠。城里老鼠说：“这东西不好吃，你的家也不好，你为什么住在田野的地洞里呢？你应该搬到城里去住，你能住上用石头造的漂亮房子，还会吃上美味佳肴，你应该到我城里的家看看。”
乡下老鼠就到城里老鼠的家去。房子十分漂亮，好吃的东西也为他们摆好了。可是正当他们要开始吃的时候，听见很大的一阵响声，城里的老鼠叫喊起来：“快跑！快跑！猫来了！”他们飞快地跑开躲藏起来。
过了一会儿，他们出来了。当他们出来时，乡下老鼠说：“我不喜欢住在城里，我喜欢住在田野我的洞里。因为这样虽然贫穷但是快乐自在，比起虽然富有却要过着提心吊胆的生活来说，要好些。”