The meaning of the saying is that we try to find out the ways and means to get those things which we need. When Nature does not give us those things that we require, we are forced to achieve them with our efforts. If a person feels hungry he is compelled to find out the ways to get food in order to satisfy his hunger. In this way necessity is the mother of invention.

There are many examples to show that necessity is behind all the activities and inventions. The story of the thirsty crow is well-known to everybody. Once a crow was very thirsty. He flew here and there in search of water. But he could not see water anywhere. After some time he saw a pitcher. He went there but he found that the water was at the bottom of the pitcher. He could not drink water. He saw some pebbles nearby. He began to drop the pebbles into the pitcher one by one. After some time the water rose and the crow drank the water and quenched his thirst. It was the pressing need of water that forced the crow to think the trick of dropping the pebbles. In the same way it is the pressing need that compels a man to find out ways and means to fulfill it.

Throughout history we find that all the inventions were made due to the pressing nature of the necessity. When man was not civilized and lived in the hunting stage the necessity of getting food to eat led him to think all kinds of tricks to catch wild animals. The necessity of preserving life against the bitterness of weather led him to make cloth to cover the body. Language was invented when there was necessity of expressing the feelings to one another. In order to keep some records, the writing was invented. Printing was invented due to the necessity of protecting themselves. Boats and ships were invented when men found the sea a hindrance in their way. To destroy the enemy and protect the country, horrible and destructive weapons were invented. New medicines and injections were invented due to the necessity of saving mankind from the hands of death. The expansion of trade and commerce was due to its necessity.

In the end we can say that all the inventions have not been due to the necessity. Today the inventing faculty in man has so highly developed that scientists feel great pleasure in inventing new things. They invent new things for the sake of pleasure whether there is any necessity or not.