Western legal systems that suggest that children who are 7 or 8 years old have attained the ability to reason are consistent with piaget's theory because basic reasoning skills appear during the period.

The answer is: concrete operational

In the concrete operational period,  people will start to develop our ability in forming our logical thought and analytic skill.

Before the concrete operational stage, children will trust almost everything that their parents told to them. After entering this stage, they will start to notice some falsehood in what their parents is saying because of their developed basic reasoning skills. Depending on their intelligence level, some children are able to solve complex problems after entering concrete operational period.

in this part of the declaration it refers to the point when american people didn't recognize the british domain and   breaks the political bands with britain, they forced a respectful separation.

mankind was created and entitled equally with rights   which were life, freedom and the seeking for happiness.