How humans decided

which way words should flow

Our writing direction was connected to the cosmic rhythms that governed ancient life. In the Northern Hemisphere, where many early writing systems emerged, the sun travels daily from east to west, casting shadows that sweep across the landscape in a right-to-left progression. This celestial movement became encoded in humanity's earliest timekeeping devices—the sundial—with its shadow rotating counterclockwise around its face.

The people designing the first writing systems—priests, astronomers, temple record-keepers—were often the same individuals who tracked these celestial movements. Their perception of directionality was shaped by years of observing the sun's journey and the resulting procession of shadows. When they put stylus to clay, might they not have instinctively followed the same directional flow that ordered their understanding of time itself?

The Greeks experimented with direction in ways that reveal the fluidity of early writing conventions. They initially wrote right-to-left, following their Phoenician teachers. Then, fascinatingly, they developed a system called boustrophedon—literally "as the ox plows"—where lines alternated between right-to-left and left-to-right. Imagine reading a paragraph where your eyes zigzag across the page, the letters themselves mirrored to face the direction of reading.

Boustrophedon writing shows us that these directional conventions weren't fixed. They evolved through a process of experimentation and adaptation.

Eventually, the Greeks settled on the left-to-right direction we now consider standard in Western writing. Why? New writing materials may have played a crucial role. As papyrus and parchment replaced clay and stone as primary writing surfaces, and as ink replaced impression-based writing, the physical dynamics changed. Now right-handed writers could avoid dragging their hands through wet ink by moving from left to right.

Meanwhile, across the world in East Asia, a completely different directional convention emerged. Chinese writing, with its origins dating back to 1200 BCE, traditionally flows vertically in columns that proceed from right to left across the page. This orientation perfectly suited the narrow bamboo slips used as early writing materials in China and complemented the brush techniques developed for calligraphy.

The material constraints of bamboo slips—narrow and long—made vertical writing the natural choice. When these columns are arranged side by side, starting from the right edge of the writing surface made sense for the same reason that right-to-left horizontal writing did—it prevented smudging for right-handed writers.

The world's various writing directions survived for millennia in their regional contexts, until relatively recent forces began to standardize them. The spread of European colonization carried left-to-right writing across the globe. The invention of the printing press, followed by typewriters and digital technologies, further reinforced these conventions, making it technically simpler to follow a single directional standard.

Today, we find ourselves in a world where the majority of humanity reads and writes from left to right, with significant populations maintaining right-to-left systems, and some contexts preserving top-to-bottom conventions. What once began as practical adaptations to materials, human physiology, and perhaps even cosmic observations has become so ingrained that we rarely question why our eyes track in particular directions across a page.

The next time you read an article online, take a moment to consider this invisible inheritance—this directional grammar that guides your eyes and hands. It connects you to those ancient scribes, to their clay tablets warmed by the same sun that casts shadows across your own sundial. In the direction of your reading lies one of humanity's oldest stories—a tale written not just in what we say, but in how we chose to say it, and write it.