How did the change in breastplates and helmets contribute to the decline of rome?

The change in breastplates and helmets contribute to decline of the Roman Empire by weakening the the military. It weaken them because the removal of it promote laziness and  negligence of training and the such. It also removes the protection against ranged weapons which caused many casualties.

new ideas form the base for the growth of the people.each time they try to develop, they may discover a new form or abilities of themselves this makes the people satisfied in living their life in a happy way.this makes sense that new ideas of people cn change their live.the ideas, if bring their best, they will be changing their present state.

The correct answer is: their civil liberties have been protected, but their civil rights are less clear apex. hope this .