Balance and Symmetry （平衡与对称）
试比较以下两段话：
1a. The national unity of a free people depends upon a sufficiently even balance of political power to make it impracticable for the administration to be arbitrary and for the opposition to be revolutionary and irreconcilable. Where that balance no longer exists, democracy perishes. For unless all the citizens of a state are forced by circumstances to compromise, unless they feel that they can affect policy but that no one can wholly dominate it, unless by habit and necessity they have to give and take, freedom cannot be maintained.
1b. The national unity of a free people depends upon a sufficiently even balance of political power to make it impracticable for there to be an arbitrary administration against a revolutionary opposition that is irreconcilably opposed to it. Where that balance no longer exists, democracy perishes. For unless all the citizens of a state are habitually forced by necessary circumstances to compromise in a way that lets them affect policy with no one dominating it, freedom cannot be maintained.
在第一段中，作者尽量平衡词组和词组，从句和从句，整体上形成一种对称的结构，读起来脉络清晰，更具行文风格。相反，第二段的写法是从句套从句，不仅读起来更加费劲，在格式上也失去了鲜明的骨架感。
试看第一段中用到的平衡和对称的技巧：
We can enhance the rhythm and grace of coordination if we keep in mind a few simple principles.（如果能够牢记一些简单的原则，则可以强化句子的韵律和协调感）
First, a coordinate series will move more gracefully if each succeeding coordinate element is longer than the one before it. So if you coordinate within a coordination, do it in the last branch of the main coordination：（在安排一系列的句子时，如果后面的句子能够比前面的较长，读起来会更加优雅。所以，如果需要在从句当中进一步调配，则最好在最后一个主分支当中展开。）
还可以通过使用both X and Y, not only X but also Y, neither X nor Y 的结构实现强调的目的：
Second, You can make these coordinate patterns more rhetorically elegant if you consciously balance parts of phrases and clauses against each other: （还可以通过韵律上的对称进一步加强句子之间的协调感：）
The richest kind of balance and parallelism counterpoints both grammar and meaning: here vacuous is balanced against mindless, emotion against eroticism, daytime against nighttime, soap opera against sitcoms, artists against audiences, able against willing, and create against support. （最彻底的平衡是在语法上和意义上都实现彼此的对比）
You can achieve the same effect when you balance parts of sentences that are not coordinated： （并且，即便是不协调的句子或片段，也可以实现彼此之间的平衡：）
1. subject balanced against an object （主语和宾语平衡）
2. the predicate of a relative clause in a subject is balanced against the predicate of the whole sentence （从句中的谓语和主句的谓语平衡）
3. A direct object balanced against the object of a preposition （句中的宾语和介词后的宾语平衡）
最后再看一例：从句和主句平衡（1a, 1b），从句宾语与介词的宾语平衡（2a, 2b），主句的宾语和两个介词的宾语平衡（3a, 3b，3c）：
