Most of the difficulties in the liberal arts are concentrated in high school.

For example, the history that Liu Fei was studying, before high school, the textbooks that were so thick every year that they were so thick that they recorded the detailed changes in various historical periods of various countries and the comments of the historiography circles.

Someone once made a statistic that the amount of text in a junior high school history textbook alone exceeded that of a 12-year math textbook.

Memorization alone is enough to break most students.

After high school, the difficulty rises again.

Memory is no longer the only thing, and the importance of a deep understanding and holistic grasp of history is becoming more and more prominent.

Take, for example, 'historical derivation'.

After the revival of Reiki, more and more historians began to reflect on whether the emergence of Reiki was inevitable or an accident under various coincidences.

They interpret the history of the world, trying to find clues about Reiki and deduce where history would have gone if humanity had made another choice at some point in history.

A handful of historians have even been able to push history back 500 years without collapsing from a certain point in the world a thousand years ago.

Twenty-eight years ago, during the Battle of the Gold Coast on the Australian mainland, the coastal joint defense line was completely lost due to negligence in prevention.

The Terrans were defeated on the Australian continent.

Ronald, the commander of the United Lines at the time and a master of the historical-historical derivation school, was forced to reverse reality by using a point in time before the fall of the Gold Coast.

With great wisdom and might, the historical line of the entire Australian continent can be broken, all the demons that invaded the interior of the continent will disappear, the destroyed united front will be restored to its original state, and even a few miracles of the dead will be resurrected.

But then the danger of the historical line being changed quickly became apparent, and the master Ronald quickly aged and died in a short period of time.

The Australian continent has been hit by natural disasters and unexpected invasions of outer space, and even problems such as historical retrospection and historical inaccuracies have occurred around the world, and the turbulence has lasted for three years.

Eventually, humanity had to abandon the continent after five years.

This is the only large-scale strategic-level practical application of the historical derivation school.

Recognized by the school of history as having a unique restorative nature, once the status quo is forcibly changed by extension, the line of history will be like a spring stretched to the limit, bounce back in a stronger posture at a certain point in time, and cause more damage.

In order to avoid the reversal of the historical line, it is necessary to master the ability of the physical school of time and space anchor, the ability of the philosophical school of cause and effect, and the ability of historical derivation.

How can there be such a perverted scholar in the world?

There have been many schools of master scholars to carry out joint academic research, but the final conclusion is still unrealizable.

The synchronicity of joint scholarship and the uniformity of the amount of Reiki used have been a major problem for Terran scholars to this day.

Add to this the fact that 'historical derivation' is not all smooth sailing, and if certain variables are ignored in the derivation, the consequences are dire.

Today, historical derivation has been defined as a restricted academic level by the 'Holy Land of Science'.

The maximum radius of use by university-level scholars cannot exceed 10 meters, and the maximum derivation time limit cannot exceed 2 minutes.

The higher the scholar's rank, the wider the scope and time of the ban, but it must not be used as a strategic academic class.

In high school, it is unrealistic to deduce history without the support of Reiki, without a comprehensive knowledge system and sufficient mental support.

Now it's more of a training.

Under the premise of giving constraints and assumptions, allowing students to deduce history within a specified range can be regarded as a kind of ability exercise.

In addition, there are many difficulties in future historiography, the identification of antiquities and aura, the manifestation and summoning of myths, the historiography of historical figures, and so on, and the overall difficulty is not easier than mathematics.

Liu Fei conducted three hypothetical derivation trainings and two more psychological deductions of major events of historical figures before he finished the morning's study.

Overall, Liu Fei's gap is still obvious.

In the derivation, there are two assumptions that the derivation has entered a dead end after entering the middle stage of history, one mainly pushes the characters to fall into a mortal ending, and the other time leads to the collapse of the historical conclusion due to the failure of the derivation conditions.

This also shows how deep the irreversible nature of history is.

Liu Fei's only success was due to the TV series he had watched, and in the limited historical derivation, the Yan State was significantly weaker than the hostile Zhou State in a certain period.

In real history, Yan was defeated in a nationwide decisive battle, and then ruled the whole country on Monday.

The historical line in which Liu Fei intervened was on the eve of the decisive battle.

It happened that according to the historical facts at that time, the decisive battlefield was located in the waters of central China, and the Zhou State plunged directly into the heart of the Yan State with its absolutely strong naval fleet, destroying the great trouble in one fell swoop.

Liu Fei remembered a certain movie called Chibi that he had watched, and there was not much nonsense in the plot, but there were many similarities between the four words of burning Chibi and the situation at that time.

Liu Fei deduced from this assumption and succeeded in breaking the Zhou State twenty years later.

This gave Liu Fei some enlightenment, in addition to the necessary historical knowledge, historical derivation also needs to have an understanding of politics, economy, society, human geography, and even romance and novels.

There are some things that are recorded in textbooks, but they will definitely not be in romance textbooks that do not conform to historical facts.

Is the Romance of the Three Kingdoms real? There are a lot of nonsense in it, even Liu Fei, a scumbag, knows how stupid it is to read the history of the Romance of the Three Kingdoms.

But if it is used in the right place like the historical derivation just now, it may work wonders.

Liu Fei took the elevator back to the ground.

The old Wang Tou was still sitting there and reading hard, and Liu Fei said hello to him and was ignored as usual.

This old man has a dead face most of the time except when he wants to eat skewers, and Liu Fei has long been used to it.

There are three rows of bookshelves in the historical area, which are all kinds of unreliable wild history, which has no reference value, and should be purely lively.

However, there are some bold and rebellious brain holes and speculations in it, which can be used in historical deduction.

Liu Fei casually found a table farthest away from the old king's head and sat down, the old man always had a stale atmosphere of rejecting people thousands of miles away, and getting too close would affect Feige's young heart.

Once immersed in the world of books, even wild history can make people addicted to it.

I don't know how long it took for the old king's hoarse cough to break the silence, and his cold voice echoed in the dilapidated library, like an old old bell: "I see the dust of history in you, and it's good." ”

Liu Fei raised his head, confused for a moment, and only after a while did he realize that the old Wang was talking to him.

Liu Fei frowned: "Speaking of human words." ”

The old Wang put down the magnifying glass in his hand, and he couldn't tell whether he was laughing or angry on his face, anyway, Liu Fei didn't see him angry all the time, as if everything was not worth it in the world except for the book in his hand.

The old king said coldly: "You can get into the dust of history in half a month, and your talent in history is rare." ”

Such a direct compliment would make people embarrassed, Liu Fei was pleasantly surprised: "Yes, I think so too." ”

The old king was rarely interested in talking, he crossed his hands and clasped them together, looked at Liu Fei and said, "Then are you still confused about your future path?"

Liu Fei groaned for a moment and said truthfully: "I don't know." ”

"Huh. The old king's head let out that creepy and inexplicable laugh again.

"In the world of scholars, pitfalls are everywhere. Those seemingly bright and gorgeous places may contain the danger of falling into the abyss if you are not careful. Now that you have been tainted with the dust of history, you are only one step away from stepping into this real world. Would you be interested in learning the real history with me?"

Is this an invitation?

Liu Fei raised his eyebrows: "I'm not interested." ”

For the first time, the old Wang Tou showed a stunned expression: "Why?"

Liu Fei smiled with a rippling face: "My target is the sea of stars." ”