Ideograms are the mnemonic stage of image writing. They may be recognizable pictures but, if so, their meanings have no relation to the picture itself. The head of an ox, for example, when it stands for an ox is picture writing, but when it stands for divinity or for the sound “a” it is an ideogram. All hieroglyphic and alphabetic writing is, therefore, in a way ideographic, but we are accustomed to distinguish phonetic writing and to leave for ideograms proper only those pictures which appeal to eye rather than ear. Some people read even alphabetical printed words as ideograms—the word suggests its object directly without being translated into its sounds. Some, on the other hand, cannot read even to themselves without thinking in sounds or even moving the lips.

Ideographic records so shade into the picture writing or the pictorial image record on the one hand and into phonetic writing and the book form common and appropriate to phonetic writing on the other, that it is not easy to single out any examples of exclusive ideographic record collections, although of course such collections are entirely conceivable, and the earliest traces of Egyptian or Sumerian hieroglyphics seem to suggest the stage where documents were in ideograms of whole words, but at this stage ideogram and phonogram would be almost indistinguishable as it would be a subjective matter as to whether it suggested to any given individual a visual image directly or only indirectly, through an ear picture.