Sefer Yetzirah: The philological

Sefer Yetzirah: The philological is discussed first, since it is necessary for an elucidation of the philosophical speculations of the work. The twenty-two letters of the Hebrew alphabet are classified both with reference to the position of the vocal organs in producing the sounds, and with regard to sonant intensity. In contrast to the Jewish grammarians, who assumed a special mode of articulation for each of the five groups of sounds, the Sefer Yetzirah says that no sound can be produced without the tongue, to which the other organs of speech merely lend assistance. Hence the formation of the letters is described as follows:

* With the tip of the tongue and the throat
* Between the lips and the tip of the tongue
* In the middle of the tongue
* By the tip of the tongue
* By the tongue, which lies flat and stretched, and by the teeth (ii. 3)

The letters are distinguished, moreover, by the intensity of the sound necessary to produce them, and are accordingly divided into:

* Mutes, which are unaccompanied by sound, such as מ
* Sibilants, such as ש, which is therefore called the "hissing shin"
* Aspirates, such as א, which holds a position between the mutes and sibilants, and is designated as the "airy א, which holds the balance in the middle" (iv. 1; in some eds. ii. 1)

Besides these three letters, which are called "mothers," a distinction is also drawn between the seven "double" letters and the twelve "simple" letters, the remaining characters of the alphabet.