A man is not idle because he is absorbed in thought. There is a visible labor and there is an invisible labor.

A man is not idle because he is absorbed in thought. There is a visible labor and there is an invisible labor.

一个人不是因为全神贯注于思考而无所事事。有看得见的劳动，也有看不见的劳动。

-- Victor Hugo 维克多雨果