Philosophy of a person's expertese

I have an interesting dilema. It seems that I have two contradictory beliefs about how someone should develope themselves as a person. My first belief is stated in Plato's Republic. In the first chapter Socrates states that people should only develope themselves to do one trait and people should focus on different areas. Thus one person would be a tailor another would be a carpenter. They can trade their services and so the tailor would get something like a chair and the carpenter would get clothing. This would eventually lead to money and a wel running sociaty. I also believe that one should be well-rounded. That is that one is a physisist but also delves a little in psychology or philosophy. Can someone help me. Do you believe the first ideology is too old-fashioned.

Contribution to science, as >>3 says, is usually due to scientists with knowledge in several fields. However, as >>2 says, you can't really achieve anything without specialising in something.

You will need to first reach a level of speciality in one field before advancing into other fields. Also by the time you are an expert in a paticular field you will be in a better position to choose which direction would be beneficial. For instance you may discover that philosophy is more closely linked to a possible avenue for scientific advancment than psychology and focus on that instead.