Learned from there mistakes and try to not repeat the same mistakes they've made
No and yes you can codices if you want
Common good means for the good of the public or the many. One example of a scenario of contributing to the common good is that a person follows the laws of the country like traffic. It is a common good because following the rules will give order thus contributes to the common good while not following the rules only served the person own's interest.
Florence is remembered as the genesis of renaissance and wealth and wealth in cities uniqueness and architecture. During the middle ages, the city was wealthy of natural resources i.e. Marble quarries where building and sculptures were made.
During this period great thinkers, philosophers, artists, architects and political figures like Leonardo da Vinci, Donantello, Ghiberti.
