Document Type : Scientific-research


1 Assistant Professor, Department of Philosophy, Ferdowsi University of Mashhad, Mashhad, Iran (corresponding author

2 Doctoral student of Hikmat Ta'alaeh, Ferdowsi University of Mashhad, Mashhad, Iran


“The Rule of the One (Qāʻîdâh Al-Wāḥîd)” regarded as one of the fundamental philosophical rules, which is not only directly or indirectly connected with several philosophical issues about God, cosmos, knowledge and so on, but also some thinkers have used it in other sciences such as Physics (Ṭâbīʻîyyāt) and Jurisprudence (Ûṣūl al-Fîqh). Although historically rooted in ancient Greek philosophy, the Rule of the One, like other philosophical rules, after the introduction of the Science of Philosophy into the Islamic world, was dealt with by Muslim philosophers.  
    The Rule of the One indicates that from a one simple cause only one effect is produced. The Muslim philosophers have often used this rule to explain how creatures are produced from a one supreme cause. However, this rule in that is related to God and His agency, can be considered as a Kâlāmī (theological) problem. Hence, most of Mûtâkâllîmūn (theologians) have discussed on it in their writings.
In spite of the significance of this rule and its several usages in real and conventional sciences, the Muslim thinkers don’t agree on it. So, in discussing on the Rule of the One, some Muslim philosophers, such as Ibn Sīnā, Sûrâwârdī and Mûllā Ṣâdrā, using the foundations of their philosophical systems, not only have accepted and proved this rule, but also have employed it in their philosophical views. But many Mûtâkâllîmūn (theologians) and mystics and even some philosophers have not accepted this rule, and consequently, have criticized it. Apparently, no book has been written about this rule by the early Muslim thinkers, but in the writings of the later Muslim thinkers, there are many works related to this rule. Of course, as far as I have searched, in most of these works, their authors have tried to criticize the Rule of the One, and in a few works, this rule has been defended. 
Since the acceptance or rejection of the Rule of the One has very important implications for the philosophical epistemological and cosmological issues, and many philosophers’ belief in this rule has been one of the main causes of the criticisms of the opponents of philosophy against the Muslim philosophers, it is necessary to classify, analyze and evaluate the criticisms arisen against this rule in order to respond to them, based on the foundations of Transcendent Philosophy.
      After classifying and examining the philosophical criticisms arisen against the Rule of the One, it was found out that, in general, these criticisms either have arisen from denying or rejecting one of the philosophical foundations of this rule (Kâlāmī (theological) criticisms) or from considering this rule as incompatible with some other philosophical rules (philosophical criticisms). In this paper, I have tried to classify, analyze and evaluate, by a descriptive-analytical method, the philosophical criticisms arisen against the Rule of the One. The findings of this paper show that these criticisms can generally be classified in two main kinds of criticism: the first kind is related to the criticisms which have been arisen against the reasons for the Rule of the One, and in which those reasons have been considered as insufficient for proving this rule; and the second kind is related to the criticisms which, apart from the reasons for proving the Rule of the One, have considered this rule as incompatible with some other philosophical rules.
According to what has been discussed in this paper, it can be said that                   
For some contemporary scholars of philosophy, the Rule of the One is incompatible with some philosophical doctrines, such as “The Simple Reality’s being All the
Things”, “The particular and immediate knowledge of God to things”, “The soul’s being, in its unity, all its faculties”, “The simplicity of the essence of Necessary Being”, “The immediate relation of the existents with the Necessary Being”, and “God’s being the Willing”.                                                
2. Some other scholars of philosophy, taking a historical approach to the Rule of the One and its origin in Greek philosophy, believe that this rule is confined to the natural causes. They argue that Muslim philosophers, such as Ibn Sīnā and Mûllā Ṣâdrā, should not applied this rule to the Divine agent, especially to the Necessary Being.
3. Some others, emphasizing on some philosophical doctrines such as “the absence of necessary concomitance between the conceptual multiplicity and the extensional multiplicity” and “the possibility of analyzing a simple essence into various concepts”, consider the production of many effects from a one simple cause as possible, and thereby, criticize the Rule of the one.
4.Finally, Some other scholars, based on some philosophical foundations, regard the essence of Necessary Being as the Comprehensive of all the Attributes of Perfection, which implies the possibility of inclusion of the multiplicity of existential perfections in a simple essence.
      At the end, I have concluded that in most of the philosophical criticisms arisen against the Rule of the One, we can see two kinds of error: “the confusion between the Concept and the Extension”; and presenting an incorrect and inaccurate image of the philosophical premises of the Rule of the One, such as “the principle of congruence”, “the impossibility of production of the simultaneous effects from a simple agent”, and “the necessity of differentiation between cognitive and objective multiplicity”.


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