Many people change their wills on their own every few years, in response to significant changes in their personal or financial circumstances.
Conclusion (therefore / should)
People should not only date their wills but also state in any new will which will it supercedes.
Intermediate Conclusion (for)
Then there would not be the problem in which the executor of the will isn't sure whether she's looking at the most updated copy of the will.
Evidence
When wills aren't dated, then the executor doesn't know which of several undated wills is the most recent, nor whether the will drawn up last has ever been found.
Evaluate
Since we're really evaluating a Plan / Recommendation, we can think of it in terms of, , or we can think of it as ?
The problem the author is trying to solve is two-fold. When an executor finds more than one will, they often don't know which of the wills is the most recent, and then don't even know if the most recent will is one of the ones they possess.
The author is saying,
Say that a will was drafted on Jan 1, 2022. But then the person wants to change it and so they draft another one on March 1, 2022. They would write on that will, .
When this person dies on Aug 1, 2022 and the executor finds both of these wills, she'll know that the March 1st one is more recent and to ignore the Jan 1st one.
But how does she know there isn't another will hiding somewhere dated ?
The executor would never know for sure whether there is still a will, not in her possession, that is more recent than the most-recent one she possesses.
Goal
Let's look for something making the objection that the executor still wouldn't know whether there's a more recent will than the most-recent one she possesses.