Yes, there were things on which some of them disagreed strongly. Despite this, they managed to reach a compromise on most issues, a consensus of sorts, in writing the Constitution.
There are some issues on which there was much disagreement, but most of those that ended up in the Constitution involved some level of consensus, or at least majority.
If I propose that a certain portion of the Constitution or BoR means "X" because this is what ten Founders had to say about what they meant by it.... then instead of telling me that the Founders don't count because they disagreed with one another, refute me by demonstrating that the FF's were not in consensus on the matter. Find a similar number of FF's that disagreed with my position and you will have negated my argument. Simply telling me that the FF's disagreed with each other on many things does not prove that they didn't agree on a specific point.
When it comes to Constitutional interpretation, what the large majority of FF's say they intended by it IS what it was ORIGINALLY intended to mean. If you don't like that or don't think it applies to modern life anymore, there's this process called AMENDMENT.
Pardon my emphasis. I am passionate on this subject, because I believe it is a respect for the strict letter of the Constitution that keeps us from the horror that is unlimited government... as it was intended to.
Well there's the issue I think of how you define a "Founding Father" people like Patrick Henry for example had a big role to play, but never actually signed or attended the signed of the Declaration of Independence or the Constitutional Convention. There's also far more to the founding of this country than those two documents, there's also the Articles of Confederation, along with the paper of the First Continental Congress, and the actions and resolutions of each state government. While its certainly easy to say some did more than others, or more accurately that their actions had more lasting effect, its hard to define a line as to who is and isn't a Founding Father. You also have other things like "Marbury v. Madison" which arguably were just as important, and had just as big of an impact, as the decisions made during and right after the Revolutionary War, should we consider those men Founding Fathers?
One quality I think most of the Founding Fathers shared however is their ability to compromise and accept that the decisions they reached, although not perfect in their eyes, would receive their personal full support.
However given the obvious amount of differences amongst the individuals most frequently called the Founding Fathers, and the fact that it took over 4 years after the end of the war, 13 since the official beginning of the country to write a document as a short as the Constitution should be testimony enough to the extreme difficulty of that task.
I take the opinion that the original intent of each Founding Father, along with their opinions on what each phrase in the Constitution specifically meant, are entirely meaningless from the perspective of legally deciding what the Constitution means. If you look at the earliest Constitutional issues, again like Marbury v. Madison, the government, which included many Founding Fathers such as Jefferson who was President at that time, accepted the decision and authority of the SCOTUS to define the meaning of the Constitution, despite the fact that none of those judges were writers or signers of that document.
The original writers who were still alive, active, in government, allowed a group of men who had nothing to do with the writing of the Constitution decide what its meaning was. Thomas Jefferson was the loudest opponent of the Marbury v. Madison decision, but even though he was President he didn't attempt to use that office to overrule that decision. So I take that acceptance and following of that decision, although unhappily in some cases, to mean the Founding Fathers have given authority of interpretation to the SCOTUS. And its been that way ever sense.
So ultimately you had a group of men who had a number of important disagreements signing a document which they couldn't even all agree on the meaning of each portion in the first place. Someone or something had to be the final authority on what the Constitution said, otherwise there would be no way the country would stay together because the delegate from Virgina told his state legislature it meant one thing and the guy from Georgia said something else. What could they do, convene a Constitutional Congress every time there was an issue? No, to impose order and rule of law upon the country only ONE institution had to have authority, and the SCOTUS was the best choice.
You can't say "I'm going along with what the Founding Fathers said" because they have multiple opinions, the SCOTUS being one body has one opinion and therefore is the better choice to follow and be given authority to make these kind of decisions both then and now.