First of all, the ancients wrote vertically because they wrote on bamboo slips before papermaking was invented. Bamboo slips and wooden slips are long and narrow pieces of bamboo, which can be rolled into books by stringing them together. The word "book" is a pictograph of bamboo slips. The roll mouth is naturally held by the right hand, and the left hand is convenient to unfold. Therefore, writing is from top to bottom and from right to left.
Secondly, judging from the characteristics of Chinese characters and people's physiological habits, because the right hand writes and the left hand holds the book, the stroke order of a word is naturally convenient from top to bottom and from left to right. If you write from right to left, when writing the left half, the brush will inevitably cover the right half, which is inconvenient to arrange the structure and affects the beauty of the knot. The last stroke of each Chinese character is in the middle or lower right, and the last stroke of the previous word is followed by the beginning of the next word. Vertical writing is more convenient than horizontal writing, and it is more convenient for the consistency of strokes.
Third, the writing of Chinese characters from top to bottom, from right to left, also reflects the ancient people's inferiority complex. In ancient times, being king and being parents; I am a priest, and I am a child. The right side is big and the left side is small. "Mismatch" means no more than. The writing of bamboo slips is bound into a book after writing one article. There is no problem of unfolding before writing, but there is a problem of arranging bamboo slips after writing. Generally speaking, the left hand holds Jane and the right hand writes. Naturally, the left hand is put down after writing. Since it's left-handed, it's probably smoother to row to the left.