عنوان مقاله [English]
In one classification, all of the sciences are divided into instrumental and original. Sciences such as logic, the principles of jurisprudence and algebra are classified as instrumental sciences, and other sciences such as philosophy, jurisprudence and arithmetic as the original ones. Instrumentality and originality are two terms that are in fact not defined clearly. To understand the criterion which distinguishes these two sciences, one must rely on the common sense of the scientologists of the two terms. Different sciences have a cooperative relationship with each other and in solving the issues of one science other sciences are involved; however, the use of one science in another cannot be regarded as a criterion of instrumentality of that science. Also, personal aims of the creators and users of the sciences cannot be a true criterion for this categorization. In the present article, by rejecting personal opinion and relativity, a general criterion for a science to be instrumental is presented. The main benefit of a science because of which the wise agree on its necessity in the body of human knowledge can be a criterion for this classification. In this article, the science of logic as an instrumental science has been the focus of discussion, although the criteria presented has nothing to do with logic.