Probably there is no one here who has not in the course of the day had occasion to set in motion a complex train of reasoning, of the very same kind, though differing in degree, as that which a scientific man goes through in tracing the causes of natural phenomena.

【翻译】可能不会有人，在一整天当中都没机会进行一些复杂的思维活动，虽然复杂的程度不同，但这与科学家在探索自然现象成因时所从事的思考活动，性质是完全相同的。

【语义分析】

1. in the course of the day：在一天当中

2. have occasion to do：有机会做某事

3. set in motion a complex train of reasoning 等于set a complex train of reasoning in motion：进行一系列复杂的思维活动

4. differing in degree：在程度上不同

5. of the very same kind as that：跟那种思维是完全相同的性质。

that指代reasoning，the same...as...  与......是相同的。

6. go through：经历；履行；从事

7. in tracing the causes of natural phenomena：在探索自然现象成因时

【结构分析】本复合句的主句很简单，它主要包含一个复杂的定语从句。

1. 主句：Probably there is no one here

2. 定语从句：who has not in the course of the day had occasion to set in motion a complex train of reasoning, of the very same kind, though differing in degree, as that which a scientific man goes through in tracing the causes of natural phenomena

在定语从句中：

3. has not had occasion被in the course of the day分隔。

4. set in motion a complex train of reasoning：句式为 set sth. in motion，因宾语太长把in motion提前。

5. of the very same kind作定语，修饰reasoning。之前有逗号相当于一个非限制性定语从句：which is of the very same kind。

6. of the very same kind as that：the same...as...句式，被省略的让步从句though differing in degree所分隔。

7. which a scientific man goes through in tracing the causes of natural phenomena是定语从句，修饰that，that指代前面的reasoning。