I'm not sure what you're reading in class which prompts this question, but I'm answering from Ben Franklin's speech before the Constitutional Convention in 1787. He clearly had some reservations regarding this new Constitution, but he does believe it should be ratified. He says the following:
"I agree to this Constitution with all its faults, if they are such; because I think a general Government necessary for us."
"I doubt...whether any other Convention...may be able to make a better Constitution. For when you assemble a number of men to have the advantage of their joint wisdom, you inevitably assemble with those men, all their prejudices, their passions, their errors of opinion, their local interests, and their selfish views.... Thus I consent to this Constitution because I expect no better, and because I am not sure, that it is not the best."
"I hope therefore that for our own sakes as part of the people, and for the sake of posterity, we shall act heartily and unanimously in recommending this Constitution."
From these statements we glean his position--the Constitution should be ratified because America needed a governing document, because nothing else was likely to better, and because it was necessary for our posterity (future generations).