In ancient systems of expression, for instance, in the scripts of the oldest languages, indefiniteness of various kinds is found with a frequency which we should not tolerate in our writings to-day. Thus in many Semitic writings only the consonants of the words appear: the omitted vowels have to be supplied by the reader from his knowledge and from the context. Hieroglyphic writing follows a similar principle, although not exactly the same; and this is the reason why nothing is known of the pronunciation of ancient Egyptian. There are besides other kinds of indefiniteness in the sacred writings of the Egyptians: for example, it is left to the writer’s choice to inscribe the pictures from right to left or from left to right. To be able to read them, we have to remember that we must be guided by the direction of the faces of the figures, birds, and so forth. But it was also open to the writer to set the pictures in vertical columns and, in the case of inscriptions on smaller objects, he was led by considerations of what was pleasing to the eye, and of the space at his disposal, to introduce still further alterations in the arrangement of the signs. The most confusing feature in hieroglyphic script is that there is no spacing between the words. The pictures are all placed at equal intervals on the page, and it is generally impossible to know whether any given sign goes with the preceding one or forms the beginning of a new word. In Persian cuneiform writing, on the other hand, a slanting sign is used to separate the words.