I.  The central question

Q: How did Wang Anshis's personal attributes influence the nature of his policies? 

A: Wang Anshih's personal character was the main reason. When he started the reforms, it was common that other scholars and politicians would came up with their own opinions. Listened to them, discussed with them and learned from them should benefit Wang Anshih's policy, but his determination rejected to respected them. Wang Anshih's stubborn and obstinate made the government policy more arbitrary and the less freedom of expression. This was also the major point which Su Tungpo against, because Wang Anshih wanted to use his own thought to replaced other people's view.

II.  The sentence

1. It's necessary to understand the nature of the political battle because the party strife shadowed Su Tungpo's entire life.

party strife  党争

shadow 这个词用得十分巧妙，苏东坡的一生的浮沉笼罩在党争的阴影之中

2. The tragedies of the political strife arose from the defects of character of a man who was unable to take good advice and unwilling to admite a mistake.

and连接的平衡结构，unable to take good advice, unwilling to admite a mistake, 用词简单，但非常简明。

3. Determination of character, we are told, is a great virture, but a qualification is necessary: so much depends upon what a man is determined to do.

有决心显然是好事，但关键在于“决心”是有条件的，它取决于决定去做什么，这就是“意志坚定”与“一意孤行”的区别。

4. The tragedy of Wang Anshih comes form fact that he was not in any way self-indulgent or corrupt himself, and that his hand was forced.

这一句的译文在语序上有些问题，容易引人误解。林语堂的意思是，王安石的悲剧并非是因为他任性放纵或贪污腐败，他的人格操守上并无不当之处，问题在于他因为被迫无奈，助长了他性格中的偏执独断。