The subordination of these three so different directions of writing to a single physiological principle is possible only in case we can show that there is only one normal direction in writing, and that the deviations from this normal direction are due to powerful causes and influences, which have prevailed over the direction primarily imposed by the structure of the brain.
It is necessary, while we are occupied with this question, to distinguish between the order of the lines and the letters and the formation of the letters themselves. The two things are in a certain degree independent one of the other. The individuality of the writer is manifested in the form, in the proportions of the letters, while the manner in which the lines and the letters are arranged one after the other displays no character of individuality.
A complete analysis of all the external influences that can have acted on the manner of writing is necessary to decide whether there exists only a single order of letters and lines imposed by nature, or whether the diversity which we see to-day is produced solely by external causes.
But the solution of this question, whatever it may be, will not suffice to furnish a detailed analysis of the cerebral functions that are put in action by writing. The formation of a letter by the hand that writes supposes necessarily that, by the movements of the fingers and the hand on one side and the visual impression of the eyes on the other, a conception of the figure produced is formed in the brain, which is retained for a certain time by the memory. The time required for the formation of the conception and the transmission from the brain of the will to produce the action is shortened by frequent exercise till the act comes to appear nearly unconscious. The more frequently a man writes, the more also will the figurative images produced by writing be fixed in his brain. But as his impressions and images are transmitted to his brain only by the muscular sensation of the single right hand—with the coöperation of the eyes, indeed—we have a right to expect that experiments and observations made on certain cerebral parts of paralytic patients will cast some light on the manner in which these figurative and largely unilateral images of the writing are formed and preserved in the brain.
For the present, we will occupy ourselves with the question. How did the ancients, how do the moderns, write? What were and what are the materials that they employ? Can we discover any connection between purely external causes and the manner of arrangement of the letters and lines?
So far as we know, representation by images has been the point of departure for all writing. Three primitive methods of writing were developed in the Eastern Hemisphere from the initial imagery: that of the East of Asia, or the Chino-Japanese method; that of the West of Asia, or the cuneiform; and the Egyptian, or hieroglyphic writing.