Chapter 5

Now there are two ways of moving along a circle, from A to B or from A to C, and we have already explained that these movements are not contrary to one another. But nothing which concerns the eternal can be a matter of chance or spontaneity, and the heaven and its circular motion are eternal. We must therefore ask why this motion takes one direction and not the other. Either this is itself an ultimate fact or there is an ultimate fact behind it. It may seem evidence of excessive folly¹ or excessive zeal² to try to provide an explanation of some things, or of everything, admitting no exception. The criticism, however, is not always just: one should first consider what reason there is for speaking, and also what kind of certainty is looked for, whether human merely or of a more cogent³ kind. When any one shall succeed in finding proofs of greater precision, gratitude⁴ will be due to him for the discovery, but at present we must be content with a probable solution. If nature always follows the best course possible, and, just as upward movement is the superior form of rectilinear movement, since the upper region is more divine than the lower, so forward movement is superior to backward, then front and back exhibits, like right and left, as we said before and as the difficulty just stated itself suggests, the distinction of prior and posterior, which provides a reason and so solves our difficulty. Supposing that nature is ordered in the best way possible, this may stand as the reason of the fact mentioned. For it is best to move with a movement simple and unceasing, and, further, in the superior of two possible directions.

1 folly   

n.愚笨，愚蠢，蠢事，蠢行，傻话

参考例句：

• Learn wisdom by the folly of others.从别人的愚蠢行动中学到智慧。
• Events proved the folly of such calculations.事情的进展证明了这种估计是愚蠢的。

2 zeal   

n.热心，热情，热忱

参考例句：

• Revolutionary zeal caught them up,and they joined the army.革命热情激励他们，于是他们从军了。
• They worked with great zeal to finish the project.他们热情高涨地工作，以期完成这个项目。

3 cogent   

adj.强有力的，有说服力的

参考例句：

• The result is a cogent explanation of inflation.结果令人信服地解释了通货膨胀问题。
• He produced cogent reasons for the change of policy.他对改变政策提出了充分的理由。

4 gratitude   

adj.感激，感谢

参考例句：

• I have expressed the depth of my gratitude to him.我向他表示了深切的谢意。
• She could not help her tears of gratitude rolling down her face.她感激的泪珠禁不住沿着面颊流了下来。