Vowel whose quality does not change over the duration of the vowel is called a monophthong. Monophthongs are sometimes called "pure" or "stable" vowels. A vowel sound that glides from one quality to another is called a diphthong, and a vowel sound that glides successively through three qualities is a triphthong. All languages have monophthongs and many languages have diphthongs, but triphthongs or vowel sounds with even more target qualities are relatively rare cross-linguistically. English has all three types: the vowel sound in "hit" is a monophthong , the vowel sound in "boy" is in most dialects a diphthong , and
The Three Types of Legitimate Rule law. On the other hand, these systems can be challenged by the appearance of a new charismatic leader, especially during economic or military crises. These 'pure types' are almost always found in combination with other 'pure types' — for example, familial charisma (important in kingship and the Indian caste system) is a combination of charismatic and traditional elements, while institutional charisma (existing in all church organizations, but absent from a priesthood that fails to develop such an organization) is a mixture of charismatic and legal elements. The Three Types of Legitimate Rule "The Three Types of Legitimate Rule" ("Die drei