Book vI chapter 1

There are some things, my most excellent Liberalis, which lie completely outside of our actual life, and which we only inquire into in order to exercise our intellects, while others both give us pleasure while we are discovering them, and are of use when discovered. I will place all these in your hands; you, at your own discretion¹, may order them either to be investigated thoroughly², or to be reserved, and be used as agreeable interludes. Something will be gained even by those which you dismiss at once, for it is advantageous³ even to know what subjects are not worth learning. I shall be guided, therefore, by your face: according to its expression, I shall deal with some questions at greater length, and drive others out of court, and put an end to them at once.

1 discretion   

n.谨慎；随意处理

参考例句：

• You must show discretion in choosing your friend.你择友时必须慎重。
• Please use your best discretion to handle the matter.请慎重处理此事。

2 thoroughly   

adv.完全地，彻底地，十足地

参考例句：

• The soil must be thoroughly turned over before planting.一定要先把土地深翻一遍再下种。
• The soldiers have been thoroughly instructed in the care of their weapons.士兵们都系统地接受过保护武器的训练。

3 advantageous   

adj.有利的；有帮助的

参考例句：

• Injections of vitamin C are obviously advantageous.注射维生素C显然是有利的。
• You're in a very advantageous position.你处于非常有利的地位。