What is Frederick Douglass's opinion of the Constitution and slavery?from the narrative of the life of frederick doouglass.

I am not sure why you keep saying that these questions are from Douglass's autobiography when they are actually from this speech he gave on the Fourth of July...

At any rate, Douglass says that lots of people think that they have to respect slavery because it is in the Constitution. But he says that the people who think that the Constitution condones slavery are wrong.  He says

if the Constitution were intended to be, by its framers and adopters, a slave-holding instrument, why neither slavery, slaveholding, nor slave can anywhere be found in it.

So he is saying that the country needs to get back to what the Constitution actually says.  He says people need to realize that the Constitution is not pro-slavery and that slavery should be abolished.