defines success. Few people couldn't do better by working hard, but it is absolutely true that some people can achieve good grades with very little effort, or certainly with less effort than others. But I think that educators should still try to instill good work habits, because even the most gifted students eventually run into challenges that cannot be surmounted except by hard work.

I have to agree with posters 4 and 5. Dedication can only take someone so far. Outside of dedication to something, someone must be able to produce, understand, and succeed at something. For example, I could be dedicated to dancing, but my two left feet make it impossible to succeed as a dancer.

It takes a degree of dedication to become truly proficient in a field. If you're just talking about succeeding educationally, some people can do it without dedication. But if you are talking about being a successful writer, or accountant, or politician, then yes, it's going to take enough dedication to engage in the hard work necessary to be successful.

People who are not dedicated can succeed if they are very talented and/or if they are born in the right circumstances.  If you are born really smart, you won't need to work as hard to succeed in school.  If you are born to a well-off family and you're exposed to books and ideas and educational opportunities all the time as you grow up, you won't need to work as hard to get good grades.  There are so many factors other than just effort that go into success or lack of it.