The Principle of Sufficient Reason and Necessarianism; Describing and Analyzing two Contemporary Approaches

Document Type : Research Paper

Authors

• Roozbeh Zare ¹
• Seyyed Hassan Hosseini ²

¹ Post doc Researcher, Department of Philosophy of Science, Sharif University of Technology, Tehran, Iran

² Professor, Department of Philosophy of Science, Sharif University of Technology, Tehran, Iran

Abstract

Highlights

The Principle of Sufficient Reason and Necessarianism; Describing and Analyzing two Contemporary Approaches

Roozbeh Zare*  ׀  Seyyed Hassan Hosseini**

Received: 20/02/2019       |       Accepted: 26/05/2019

Abstract

In contemporary analytic philosophy, the principle of sufficient reason (PSR) has been attacked due to its controversial results. Among these results, necessarianism (modal collapse) is the most significant one. Indeed, our intuition indicates that there are some things around us which are contingent which means that they could be in another way. Accepting the PSR seems to conflict with this common intuition; if all things have a sufficient reason, is it possible to have contingency or would all things be necessary? In response to this problem, several answers have been presented which we will recount briefly in this paper , nevertheless the main points that we have emphasized in this paper are: 1. explaining the problem of necessarianism based on the text of one of the pioneer thinkers in this regard (Van Inwagen) who refuted the principle and 2. an answer to this problem from one of the most important researchers on the issue (Pruss) who tries to solve the problem by denying causal necessity. Finally, we examine the solution of Muslim philosophers especially Ibn-Sina (Avicenna) who solved the problem without refuting causal necessity.

Keywords

Principle of Sufficient Reason (PSR), Necessarianism, Modal Collapse, Peter Van Inwagen, Alexander Pruss.[1]

Introduction

The simple formulation of the principle of sufficient reason (hereafter, PSR) is that "e must have a reason or cause." If we accept a tempered version of this principle, we will seek a reason for any fact. Although PSR was coined by Leibniz and he was the first to call it by this name and, arguably, the first to formulate it with full generality, it should be noted that the content of the principle goes back nearly as far as philosophy itself.

The refutation of PSR has too many negative consequences. Suppose that "there are somethings that don’t have a reason"; we also know that "there are some things that have a reason". Therefore, by refuting PSR we face the issue of criterion: when is it acceptable and when it is unacceptable for something to not have a reason? Those who deny this principle must place the limits where is not arbitrary or questionable.

According to some critics of PSR, acceptance of the principle is too costly due to its radical implications. These are said to include: 1) failure to conform to the findings of modern physics (quantum indeterminacy), 2) necessarianism, and 3) the existence of God. In this article, we will concentrate on necessarianism, which is considered to be the most important contemporary objection to PSR.

Summary

Necessarianism briefly means that there is no contingent being, and all beings are necessary; sometimes it is expressed as that there is no true contingent proposition and all truths are necessary. Necessarianism is refuted in two ways: 1) it is against the intuition that there are contingent beings or truths, and 2) with the addition of some other premises, it is placed against the intuition that we are free agents. In this article, we will not consider the second objection, which requires the explanation and deliberation of the consequence argument.

Inwagen is one of the main contemporary critics of PSR and his denial is mainly based on the problem of necessarianism. He believes that PSR has the consequence that all true propositions must be necessarily true. In short, his argument is that if there is a contingent proposition, then there is a set of all contingent propositions, but the explanation of any set of contingent propositions must be based on a contingent proposition outside of that set; therefore, the set of all contingent propositions cannot be explained. Hence, since, according to PSR, only those things can exist that have an explanation; only the necessary truths can exist.

Inwagen founds his argument on two claims about the nature of the contingent propositions:

1.  A contingent proposition cannot explain itself.
2.  A contingent proposition cannot be explained by a necessary proposition.

Similarly, both claims are grounded on the belief that if Q explains P, then Q entails P. Here entailment means that P is a logically necessary consequence of Q (explanation is equivalent to logical implication). By rejection of this belief, Pruss proposes his tempered version of PSR.

Pruss explains that sufficient reason needs to be understood not as ‘necessitating reason’ but as ‘sufficient explanation,’ where we understand that a causal account is always sufficiently explanatory, even in an indeterministic approach. Hence, if you have found the cause of an event, then you have sufficiently explained it even though one may not be able to explain why another event has not taken place instead of this contingent one. Therefore, the key component that is refuted in Pruss’s proposal, is the lack of contrastive explanation (to explain why a proposition is just so and also why it is not otherwise).

According to this explanation, Pruss will be able to refute both fundamental claims of Inwagen’s argument. For instance, the truth of (2) depends on whether we accept that if Q explains P, then Q necessarily entails P. As we have already seen, it is not necessary for Pruss that an explanation logically entails what it explains, thus, a proposition may explain itself without logically entailing itself.

The response of Avicenna to necessarianism, in a nutshell, is that his modal ontology allows for contingency in the following sense: some existents are contingent where ‘contingent’ means possible in itself and necessary through another. According to him, all creatures are contingent when considered alone and necessary when their sufficient causes are considered. Both of these claims are compatible with our intuition and there is no need to sacrifice one for another. Causal determinism and therefore non-restricted PSR is compatible with the intuition of some beings being contingent in themselves.

-  Marmura, M. E. (2005). The Metaphysics of the Healing: A Parallel English-Arabic Text (al-Ilahihyat min al-Shifaʾ). Brigham Young University Press.

-  McGinnis, J. (2010). The Physics of the Healing: A Parallel English-Arabic Text (al-Tabie‘eḥyat min al-Shifaʾ). Brigham Young University.

-          Melamed, Y. Y., & Lin, M. (2016). Principle of Sufficient Reason. Stanford Encyclopedia of Philosophy. N.P.

-          Pruss, A. R. (2006). The Principle of Sufficient Reason: A Reassessment. New York: Cambridge University Press.

-          Richardson, K. (2014). Avicenna and the Principle of Sufficient Reason. The Review of Metaphysics, 743-768.

-          Van Inwagen, P. (1983). An essay on free will. Oxford: Oxford University Press.

-          Van Inwagen, P. (2018). Metaphysics. New York: Routledge

Keywords

• Principle of Sufficient Reason (PSR)
• Necessarianism
• Modal Collapse
• Peter Van Inwagen
• Alexander Pruss

Main Subjects

• philosophy of Religion