Muslim scholars have developed a spectrum of viewpoints on science within the context of Islam. The Quran and Islam allows much interpretation when it comes to science. Scientists of medieval Muslim civilization contributed many new discoveries in science. From the eighth to fifteenth century, Muslim mathematicians and astronomers furthered the development of almost all areas of mathematics. At the same time, concerns have been raised about the lack of scientific literacy in parts of the modern Muslim world. Islamic scientific achievements encompassed a wide range of subject areas, especially medicine, mathematics, astronomy, agriculture as well as physics, economics, engineering and optics. Aside from these contributions, some Muslim writers have stated that the Quran made prescient statements about scientific phenomena that were later confirmed by scientific research for instance as regards to the structure of the embryo, the solar system, and the development of the universe. According to Toby Huff, there is no true word for science in Arabic as commonly defined in English and other languages. In Arabic, "science" can simply mean different forms of knowledge. This view has been criticized by other scholars. For example, according to Muzaffar Iqbal, Huff's framework of inquiry "is based on the synthetic model of Robert Merton who had made no use of any Islamic sources or concepts dealing with the theory of knowledge or social organization." Each branch of science has its own name, but all branches of science have a common prefix, ilm. For example, physics is more literally translated from Arabic as "the science of nature", علم الطبيعة ‘ilm aṭ-ṭabī‘a; arithmetic as the "science of accounts" علم الحساب ilm al-hisab. The religious study of Islam is called العلم الديني "science of religion" (al-ilm ad-dinniy), using the same word for science as "the science of nature". According to the Hans Wehr Dictionary of Arabic, while علم’ ilm is defined as "knowledge, learning, lore," etc. the word for "science" is the plural form علوم’ ulūm.