道德问题

I shall define him as an individual who has elected as his primary duty and pleasure in life the activity of thinking in Socratic way about moral problems.

译文我会把他定义为一个对道德问题进行苏格拉底式思考，并将此作为自己人生首要责任和乐趣的人。

点睛

define sth./sb. as....意为“把某事物/某人定义/解释为…”。who引导的是以individual为先行词的定语从句，其中the activity of_为宾语，介词短语as...in life是其补语。elect此处意为“选择”，而非“选举”。