There are many sciences devoted to the study of the Qur'an itself. The development of such sciences dates from the first day of Qur'anic revelation; over a period of time they were unified and perfected. Today countless books are available on these sciences, fruit of the labour of different researchers over the centuries.
Some of these sciences investigate the language and vocabulary of the Qur'an, and some the meanings. Those concerned with language are the sciences of correct Qur'anic pronunciation and reading (tajwad and qira'ah). They explain the simple changes which certain letters undergo when occurring in conjunction with others, the substitution of letters and the places prescribed for breath-pausing, and other similar matters. They also study the different ways the Qur'an has been written down and the several generally accepted ways of recitation, together with the three lesser known ways and the rarer modes of recitation.
Other works enumerate the number of chapters and their verses, while others relate these numbers to the whole Qur'an.
They discuss the tradition of Qur'anic calligraphy and how it differs from the normal Arabic script. They research, too, into the meanings of the Qur'an and the general division of subject matter, such as the place and circumstance of revelation, the interpretation of certain verses, the outward and inner meanings, the muhkam (clear) or the mutashabih (ambiguous), and the abrogating and the abrogated verses.
Others study the verses containing the laws (which, in fact, are part of what is known as Islamic fiqh or jurisprudence). Others specialize in the commentary of the meanings (already seen in a previous section of the book). Specialists in each of the different sciences have published numerous works on each subject.
* The Qura'n in Islam, It's Impact and Influence on the Life's of Muslims. By Allamah Sayyid M.H. Tabtaba'i. Ansariyan Publications. P.O.B 37185/185/187 QUM. Islamic Republic of Iran.