think for yourself 和think by yourself 的区别````

问题描述:

think for yourself 和think by yourself 的区别````
还有就是,think for yourself 除了为自己着想的意思外,有没有独立思考的意思?
哪位达人帮忙解答,不胜感激

think for yourself貌似是为自己着想
think by yourself 貌似才是独立思考