It is less sexy and less popular, but the engineer that invents a more efficient manufacturing or distribution process that slightly reduces the resources used in products enjoyed by millions of people, perhaps becoming rich in the process, does far more good for the world than an elementary school teacher. Sam Walton did more good for humanity than any thousand average teachers combined.
Had Sam Walton been a teacher, teaching thousands of children throughout his life, what are the chances he would have inspired some them to be great engineers?
If becoming a teacher is the ultimate instrumental good, then we would all become teachers, then nothing would get done.
Since that is obviously the worst of all worlds, it tells me that teachers do a good thing, but not the greatest thing.
However, without teachers, few things would get done as everyone would reinvent the wheel. This is also, while not the worst scenario, it is far from the best.
Thus, the best scenario seems to be that people should try to accomplish something, then go back and teach the next generation. The bonus is that these people will know how to get to the top.
However, people who are good at getting things done are not necessarily the best teachers, and for the people that are...
Perhaps, like we have today, those who are good at teaching and want to should teach, and those who want to produce should produce (and then later teach). The whole system relies on there being a good balance between the two. How to calculate the balance is very hard.
Well, of course you are right that everyone can't be a teacher. However, realistically, I think we are very much on the opposite end of number-of-great-people-who-are-teachers spectrum.
Also worth pointing out that this isn't necessarily true for secondary education - Universities are institutions which allow great teachers to both do great work and teach. I'd hypothesize that if the same were extended to other institutions, and also to younger students, much value would come of it.
Lower than the chances that people have been influenced by him as the creator of one of the greatest modern companies. He has far more reach where he is.
As a side note, this approach made him richer, too.
