Kalos k' agathos is also known in contemporary greek as one word.. kalokagathos. It means 'good and naive'. In context this usually is used to refer to someone who is a kind person by noble purpose. I think you have confused the phrase "a strong mind in a healthy body" which is Nous igeiis somati igeis actually meaning that a prerequisite for a healthy mind is a healthy body.

Hello, I was hoping some one could help with an ancient phrase. I believe it is "kalos 'k agathos." I remember it being a phrase the encompassed the overall philosophy of ancient Greece. In general, it is supposed to mean "a strong mind in a healthy body." Could anyone confirm this. Or if I am mistaken, can anyone let me know exactly what the ancient phrase is? Thank you