An Analysis and Study of Fakhr Razi’s and Khwaja Nasir Tusi’s Theory Regarding Notion and Assertion

The division of knowledge into “notion” and “assertion” is one of the foundational discussions. Knowledge, in its general sense, is divided into knowledge-by-presence and acquired knowledge. Acquired is either notional that is not judgment or notional accompanied by judgment. The former is “notion” while the latter is “assertion.” The two problems of this division are as follows: 1) “failure to comply with the criteria of rational division” which includes the instances of “unity of the divider and divided” and “lack of contrast between the types; 2) “the contrast of two categories in one quiddity.” Thinkers have replied to the first problem by considering the different validities in division, that is, the divider is unconditioned, notion is negativity conditioned, and assertion conditioned to something. In response to the second problem, they have said that judgment is necessary to assertion and is tantamount to the differentia, and the companionship of notion and judgment is mental.
Apart from asserting the composition of assertion and explaining its parts, Fakhr Razi believes in the logical requisites of composition as well. According to him, assertion is the collection of notions of object and predicate and copula and judgment. Its problem is the acquirement of assertion from definition dues to the self-evidence of judgment; or it is from both definition and argument due to the acquiredness of judgment. As it were, the acceptance of the acquirement of judgment is incompatible with Fakhr Razi’s foundation in considering notions self-evidence. Another problem is the incompatibility with the unity and simplicity of knowledge. In his view, we cannot eliminate the first problem by considering the different validities in the divisions and divider because firstly, the type of these conditions is mentally-posited and they cannot be the differentia for real matters. Secondly, these validations explain the manner of presence of the divider in the divisions and their relationship to each other and is not specific to notion and assertion. Similarly, using judgment as the diffrentia of assertion cannot be a reply to the second problem because no differentia has been mentioned to conceive a part of assertion to make it acquired and distinct. Moreover, because Fakhr Razi’s basis has a problem in the composition of assertion, answers and requisites based on it will also be problematic. Therefore, his view does not appear to be successful in solving the problems.
In the explanation of the views of the philosophers, Nasir al-Din Tusi considers assertion to be judgment. “Meaning” is the divider of notion and assertion. Notion is really knowledge and assertion is knowledge of it reverts to notion. In reality, assertion is judgment and judgment has two aspects: 1) it is an action of the soul; 2) conceptualization of this action of the soul by the soul. According to the second aspect, judgment is one of the instances of notion.
The main point in this view is to consider notion as the basis; however, limiting knowledge to notions results in the denial of the share of argument in the two parts of logic. As it were, the division of knowledge into two parts makes the division figurative and indulgent. However, if one seeks the different in the philosophical and logical aspects in Khwaja Nasir’s view, then from a philosophical perspective, assertion is judgment and reverts to notion and this results in the exclusiveness of knowledge to notions. Therefore, there are essentially no divisions for knowledge. However, the concept of notion and assertion is one of the issues of logic. From this perspective, knowledge is figuratively divided and since it is in the beginning of logic and is in the position of education, such a matter is allowed. Therefore, by defining “meaning” as a divider, Khwaja could answer the first part of the first problem. As it were, considering assertion to be the same as judgment is both its second part and also the second problem which is an existential and ontological discussion would essentially not be applicable.