上句见：Day197
The Story of Philosophy《哲学的故事》的第198句：第1章Plato第3节III. The Preparation of Plato第1段第4句：

Plato's meeting with Socrates had been a turning point in his life. He had been brought up in comfort, and perhaps in wealth; he was a handsome and vigorous youth — called Plato, it is said, because of the breadth of his shoulders; he had excelled as a solider, and had twice won prizes at the Isthmian games. Philosophers are not apt to develop out of such an adolescence. But Plato's subtle soul had found a new joy in the "dialectic" game of Socrates; it was a delight to behold the master deflating dogmas and puncturing presumptions with the sharp point of his questions; Plato entered into this sport as he had in a coarser kind of wrestling; and under the guidance of the old " gad-fly" (as Socrates called himself) he passed from mere debate to careful analysis and fruitful discussion. He became a very passionate lover of wisdom, and of his teacher. "I thank God," he used to say, "that I was born Greek and not barbarian, free man and not slave, man and not woman; but above all, that I was born in the age of Socrates."
浙江大学译本：但柏拉图那敏感细腻的心灵被苏格拉底的“辩论式”竞技所吸引，目睹他的老师用尖锐刻薄的问题将传统的教条和臆想一一戳破实在是一种愉悦，于是，柏拉图像从前投身野蛮摔跤比赛那样迈入了这项竞技活动。在老“牛虻”（苏格拉底的自称）的教导下，他从只求胜利的辩论者逐渐转变成思想者，不再只是纯粹的辩驳，而是能够进行细致的分析，还能展开卓有成效的讨论。

解析

这句话解释了柏拉图在苏格拉底辩论法的影响下的转变。
1、But Plato's subtle soul had found a new joy in the "dialectic" game of Socrates;
新乐趣：然而柏拉图敏锐的心灵让他在苏格拉底的“辩论法”的游戏中找到了新乐趣。
dialectic：a method of examining and discussing opposing ideas in order to find the truth辩证法
The little boy crowed with delight at the success of his dialectic. 小男孩因辩证法的成功而欢呼雀跃。《人生的枷锁》

2、it was a delight to behold the master deflating dogmas and puncturing presumptions with the sharp point of his questions;
大快人心：看着这位大师用他那些问题的尖锐点驳斥了各种教条同时戳破了种种臆断，是一种愉悦。
behold：to look at/see something 看
The woman looked at Yeobring, and beheld him colorless, in a cold sweat.那位妇人看了看约布赖特，只见他面无血色，一头冷汗。《还乡》
deflate：to show that (something) is not important or true 驳斥，打击
I find that the mirror habit can deflate conversational energy or make it feel choppy.我发现照镜子的习惯会削弱谈话的能量或让人感觉断断续续。
puncture: to weaken, damage, or destroy (something, such as an argument or a person's feelings, pride, etc.) suddenly or in a way that causes surprise or embarrassment.打破了，戳破
But they punctured other bits of received wisdom.但是他们打破其他的一些公知。《经济学人》

3、Plato entered into this sport as he had in a coarser kind of wrestling;
投身新运动：柏拉图像以前投身一种较为粗野的摔跤一样投身于这种运动。
coarse：rude or offensive野蛮的，粗俗的
There was something vital and earthy and coarse about him that appealed to her.他身上有种生气勃勃的粗俗味儿吸引着她。《飘》

4、and under the guidance of the old "gad-fly" (as Socrates called himself) he passed from mere debate to careful analysis and fruitful discussion.
并且在老“牛虻”（苏格拉底这样称呼自己）的引导下，他把单纯的辩论变成了仔细的分析以及富有成效的讨论。
gad-fly: any of various files (as a horsefly, botfly, or warble fly) that bite or annoy livestock牛虻； 当说某人时，是指someone who annoys people by being ver critical有意搅扰他人者

然而柏拉图敏锐的心灵让他在苏格拉底的“辩论法”的游戏中找到了新乐趣。看着这位大师用他那些问题的尖锐点驳斥了各种教条同时戳破了种种臆断，是一种愉悦。柏拉图像以前投身一种较为粗野的摔跤一样投身于这种运动。并且在老“牛虻”（苏格拉底这样称呼自己）的引导下，他把单纯的辩论变成了仔细的分析以及富有成效的讨论。