one must rely on both oneself and others to be successful
1. one must rely on oneself, only rely on others won't work....
2. one must also rely on others due t (a) teamwork important, complex tasks can't be achieved by a signle person, blabla.. (b) no body is perfect, others can help you improve, blabla
3. these two are not either-or choices. actually one must emphasize both to be successful.