What is ilm al-kalam?

Scholars have differed concerning the ruling on learning Kalam (scholastic theology). Some consider it forbidden, others obligatory, and some have provided a detailed view, deeming it permissible for those of sharp intellect, well-versed in the Qur'an and Sunnah. Others hold that the prohibition of this science was specific to what philosophers composed, whereas what Muslims refined from it is necessary for correcting beliefs and for the mind to grasp subtle points. Still, others have opted for the view that learning this science is not beneficial due to the confusion it brings upon its practitioner, citing the statements of Al-Ghazali, Al-Shahrastani, Al-Amidi, and Imam al-Haramayn al-Juwayni, all of whom concluded that knowledge of the truth is not attained through Kalam.