Phlox or Dame's Rocket ?

Now here is what happens sometimes in our garden. A few years ago we planted some seeds. These are the flowers that keep appearing year after year since then. They are about 5 feet tall and only bloom in late spring. They are very prolific and easy to transplant. Some have told me they are phlox (the non-creeping variety) but we had also planted some Dame's Rocket, so we are not sure. Whatever they are they have a very showy display each year and we are thankful that they decided to make their home with us.