Historical contingency and inevitability are two sides of the same contradiction, inevitability is the main aspect of this contradiction, contingency is the secondary aspect, and they complement each other and are indispensable. From the perspective of historical materialism, human society is constantly moving and developing, and this kind of movement exists regularly, so the regularity of human society determines the development trend of history, that is, history is dominated by inevitability. On the other hand, the subject and creator of history are the people, and the diversity of the people also requires the existence of accidental factors in history.
If history is a rolling river, then the inevitability of history is the mainstream of this river, which determines where this river flows, while the contingency of history is the countless tributaries on both sides of this long river, which makes this river colorful.
In thousands of years of human civilization, our society has developed from the primitive stone civilization to the present industrial civilization or information society, which is the inevitable development of history. But in this process, because of fate, a group of great heroes emerged. Is it a historical necessity? No, of course not. Who can go down in history is accidental. As individuals, we may just be a trickle in this long river, so we need to conform to the mainstream, that is, respect the laws of history and not move against the historical trend. However, the contingency of history can also allow us to give full play to our subjective initiative, do our best to develop ourselves, make contributions to the whole society, and become a shining member of the stock trickle.