We all discover hammers early in life, sometimes to our parent's distress.
Hammers are, of course, used to drive nails mainly into wood to hold things together. They are used to bang things into place, break windows in emergencies and deliver a well-focused punch to some resisting object. People also hammer points home in arguments. In Japan the nail [person or issue] that stands up cries out to be hammered down.
We are taught to respect and be careful of the hammer because if it is misused, it can be quite dangerous.
One wonders when the hammer, as we know it, was first invented. Obviously, it was preceded by almost any hard object used to bang on or break some other hard object. One hopes the genius who figured how to combine all the elements into the modern hammer made out like a Steve Jobs in his/her day.
The value of a hammer, and what it can do, has been an interesting question for quite a long time. Generally, the use of the hammer is seen as just one small step in more extensive undertakings, and therefore it is not singled out for any special recognition or value.
Some years ago, a small specialty chemical company in Massachusetts built a new plant which was having trouble getting started after its completion. The managers hemmed, hawed, and fussed to no avail. Then the CEO had the idea to call in an MIT professor he knew to take a look. The Professor drove out to the plant about an hour away. He then walked around the plant for a half hour scrutinizing all its steps and pipes and then asked for a ladder and a hammer. They were supplied. He carefully put the ladder up against one particular pipe, climbed half way up the ladder, and sharply struck the hammer once on that pipe. Immediately there was a loud gurgling noise, which he told the managers indicated the plant was finally working. Then he went back to MIT.
About 10 days later the CEO received his bill which simply said "For services: $10,000." The CEO thought that was pretty steep, so he consulted his board for advice. They suggested that he request itemization.
The professor immediately complied. "Services rendered: $5 for the hit with hammer, $9,995 for knowing where to hit."
The bill was promptly paid.
So much for taking hammers for granted. Without the hammer, the $9,995 of knowledge would have been worthless!