The Chinese roots of Japanese calligraphy go back to the twenty-eighth century BC, to a time when pictographs were inscribed on bone for religious purposes. When this writing developed into an instrument of administration for the state, the need for a uniform script was felt and Li Si, prime minister in the Chinese dynasty of Qin, standardized a script and its way of being written. He sanctioned a form of script based on squares of uniform size into which all characters could be written from eight strokes. He also devised rules of composition where horizontal strokes are written first and characters are composed starting from top to bottom, left to right. Because the symbols were inscribed with sharp instruments, the lines were originally angular and in many ways, Li Si's achievements were made obsolete by the appearance of brush and ink (see Chinese calligraphy). The ink-wet brush creates a line quite different from a sharp stylus. It affords variation in thickness and curve of line. Calligraphy retained the block form of Li Si and his eight strokes but the writer was free to create characters that emphasized aesthetically pleasing balance and form. The way a character was written gave a message of style.