why does franklin believe that any constitution the convention approves will be an imperfect document?

Benjamin Franklin believes that any constitution the Convention approves will be an imperfect document because human beings are inherently fallible and prone to errors, prejudices, passions, and selfish views. He recognizes that since the constitution is created by a group of people, it will inevitably reflect these limitations and imperfections. Franklin ultimately consents to the Constitution despite its faults, believing it is necessary and likely the best possible option under the circumstances. In his farewell speech at the Convention, he famously expressed, "I agree to this constitution with all its faults, if they are such... because I expect no better, and because I am not sure that it is not the best".