What do you suppose he meant by saying "we have probably had too good an opinion of human nature in forming our confederation"?

When George Washington said this in a letter addressed to John Jay on August 15, 1786, he probably meant that when they formed the confederation, they thought of the human nature too upright when in fact not since part of human nature are its negative characteristics such as its being selfish and self-seeking.   

if you are on the computer you can not take a picture but you can upload one but i am not sure about phones but i'm pretty sure it's the but to upload one just click the paper clip looking thing/ link thingy thing and upload a pic

during the nancy. probs