In the field, it is frequent to see many animals that are near a fire that is extinguishing, until last flame of its ashes vanished and leaves them trembling in the darkness. But none of them has ever planned to add another branch to maintain it lit. Costs to think that primitive man had not proceeded otherwise. It is been so habituating to the fire that one ends up thinking that his ancestors have always had it, and felt maybe surprised to the knowledge that was one of the things that they had to discover.
 
However, during many centuries, the men didn't have fire. They didn't know how to make it, as a bear or a cow don't know how to make it either. If one thinks for a moment of what should be their life without fire, and it is remembered only something of all that has made for the human beings, you will be able to agree with me in that it can be considered as the man's more important discovery. 

Certainly that before the man discovered it, there  was  fire  in  the  world... from  time  to  time. Sometimes, a lightning set on fire a dry tree, and the rain was too light to avoid that a fire  spread for the forest. Other times, the lava of a volcano or a meteor from the sky caused a fire.  However, these events should be so strange that only a few men saw one. And that who saw it, surely ran terrified to take refuge as the other living things.

Certainly that before the man discovered it, there  was  fire  in  the  world... from  time  to  time. Sometimes, a lightning set on fire a dry tree, and the rain was too light to avoid that a fire  spread for the forest. Other times, the lava of a volcano or a meteor from the sky caused a fire.  However, these events should be so strange that only a few men saw one. And that who saw it, surely ran terrified to take refuge as the other living things.

He maybe noticed, simply that his hands warmed when he rubbed them forcedly one against another and perhaps he thought that with two sticks he could achieve the same thing. The fact is that, finally, he was able to rub the sticks with so much strength or to make rotate one with a notch with so much speed that the dry wood began to burn. Many thinkers and myself believe that it in this way man discovered fire.

How did I reach this brilliant conclusion? well, is just that in this way the North American Indians  accustomed to light it, and in fact, almost all the ethnic groups not civilized that live in the islands of the Pacific ocean and that ignore more modern methods, as a simple lighter, still obtain it in that way. Some natives although they know how to make it, travel many kilometers to request fire when theirs goes out, because to light it is not an easy task.

Soon, he was able to discover that he could make valuable things with that burning branch. At least he could shake it and scare the most ferocious animals; he could add other branches to conserve it  during a longer time; put it at the entrance of his cavern, and maintain far enough the wild animals while he and his children slept at night. And when he lay near the warm coal, he felt so pleasure as he had never been during the hours lived in the cold darkness. For those reasons, he maintained the fire during a lot of time before he used it to cook his food.

Soon, he was able to discover that he could make valuable things with that burning branch. At least he could shake it and scare the most ferocious animals; he could add other branches to conserve it  during a longer time; put it at the entrance of his cavern, and maintain far enough the wild animals while he and his children slept at night. And when he lay near the warm coal, he felt so pleasure as he had never been during the hours lived in the cold darkness. For those reasons, he maintained the fire during a lot of time before he used it to cook his food.

It was not an easy task him to conserve his fire day and night, in rainy time, and to hunt at the same time. But it was something truly important for him, because, if it extinguishes, he would have to wait a meteor, a volcano or a lightning to be able to light it again; and as you can imagine the possibility that something like that happened was very scarce. For that reason, he wanted to share his fire. While more
people had it, it would be more difficult that it ended up extinguishing. And soon, all wanted to have fire when making sure of its virtues. And this way, when the blaze of someone went out, he lit it again using the fire from a neighbor.

It should not take long in taking place an accident that allowed to cook something. Maybe, some meat pieces fell on the fire and later their flavor was more pleasant. Or somebody left one night some meat piece near the fire and the following morning that guy woke up with a new form of feeding. Soon, in some form, all men liked it more the meat if it had been exposed to fire. Finally, somebody had the idea of placing the meat over it and to leave it to burn. It was the first cook. Even such an intelligent man as this didn't know how to light the fire. If he already had one, he could be able to light another with it; but if it was not he was condemned to pass cold the rest of his life. Many centuries passed before men learned how to light a fire without using another.

Here are all the consequences of having shown curiosity before a branch that burned. However... What would the man be without the fire? A savage. He would not have more heat than that from the sun, neither light. He could only have raw foods and he would have to live in the warm countries, easy prey of the predator animals. He could not make almost anything with the metals that the earth contains. He would not have iron, nor brick, nor mosaic, neither glass. He would lack most of the thousand things, without those which life is almost inconceivable. He would be still a savage and it would continue being it for the rest of his existence through the centuries.