Why stopping the cause is better than repairing the results

I like this old allegory poem - a powerful reminder of a universal rule which we often ignore while trying to resolve the ongoing problems.  

The Ambulance Down in the Valley

"Twas a dangerous cliff, as they freely confessed,
Though to walk near its crest was so pleasant,
But over its terrible edge there had slipped,
A duke and full many a peasant.

So the people said something would have to be done,
But their projects did not at all tally.

Some said, "Put a fence around the edge of the cliff,"
Some, "An ambulance down in the valley."

But the cry for the ambulance carried the day,
For it spread through the neighbouring city,
A fence may be useful or not, it is true,
But each heart became moved with pity,

For those who slipped over that dangerous cliff;
And the dwellers on highway and alley
Gave pounds and gave pence not to put up a fence,
But an ambulance down in the valley.

Then an old sage remarked, "it’s a marvel to me
That people give far more attention
To repairing the results than to stopping the cause,
When they’d much better aim at prevention.

"Let us stop at its source all this hurt," cried he.
"Come, neighbours and friends, let us rally.
If the cliff we will fence, we might almost dispense
with the ambulance down in the valley."