Can someone explain in more detail why under the parol evidence rule, a merchant would not have to adhere to oral statements made before a written contract was made if the written contract appears to be a total integration of the entire deal?

I do understood the parol evidence rule, but what is that mean by "adhere"?

Thanks for your help

The parole evidence rule is pretty ridiculous but i can tell what you need to know.  I just took REG yesterday.

Beckers verbage is pretty slack but after studying a few time i got most of the jist.  Essentially its a rule that no evidence can be admitted in court, oral or written that are seek to change any part of a contract already in effect (what becker refers to as a condition precedent that would seek to change the terms or prior contemporaneous statements).  As long as you know that and that the only evidence that can be admitted before is evidence that explains abiguity or things that are not clear.  Oral and written statement, conditions subsequent, can be admitted into evidence.  If you know those things, you are good to go.   

In a nutshell:

The car salesman can tell you anything before you sign the contract for that slightly-used Mercedes (you get a 5,000,000 mile warranty and free car washes every week forever).  You can ask for free rides to the moon as well.  These are considered terms of negotiation, and are NOT binding.  "Not binding" => merchant does not have to "adhere" to them.  "Adhere" definition: to stick, as in Adhesive Tape.

You'd better READ that contract and make sure those "condition precedent/concurrent" represented provisions are actually IN the contract when you sign it.  The signed contract is considered the FINAL agreement which came out of the negotiations.  If free car washes and rides to the moon are not in the final contract, you don't get them.

Now if the free car washes and rides to the moon are agreed upon AFTER the contract is signed ("condition subsequent"), that is entirely different.  Those are treated as an amendment to the already-signed contract, and you CAN seek to enforce those terms.

Here is my two sense:

Terms of a K (contract) set forth in a writing intended as a final expression of the parties cannot be contradicted by evidence of any prior agreement or contemporaneous oral agreement.

However, an exception exists. The terms of the K may by explained or supplemented by consistent addtional terms, course of dealing, usage of the specific trade or business, or course of performance.

I hope this helps and does not add to your confusion.