Theism and the Cumulative Argument

In recent scholarly discourse, natural theology’s forefront initiative has been the construction of theistic arguments grounded in empirical observations. A notable focus within this domain is the cumulative argument (CA) approach. The CA posits that individually modest arguments, when synergized, can forge a more compelling collective case. This approach bifurcates into deductive and probabilistic methodologies, both scrutinized through a descriptive-analytical lens across three evaluative tiers: 1) Merits: The CA challenges atheistic and agnostic skepticism, bolstering theistic convictions. 2) Solvable critiques: The CA process is complex and challenging for the general public; it overlooks competing hypotheses, and a mere 50% likelihood assigned to premises fails to substantiate conclusive acceptance. 3) Critiques: The CA blurs distinctions between belief accuracy probability, and rationality degree; it also grapples with assigning definitive values to probability multipliers. This paper culminates with an exploration of the CA’s implementation within Islamic intellectual traditions, illustrating its application in affirming divine existence and underpinning methodologies like suspicious density and prophetic veracity, ultimately aiming to convince counterparts through reasoned dialogue. Although it has some limitations, CA is both rational and defensible when it effectively reinforces core theoretical beliefs and religious practices, including worship and ethics.
 
Introduction
This article aims to analyze and critique the deductive and probabilistic formulations of the cumulative argument in natural theology. Additionally, it explores the historical application of the cumulative argument within Islamic thought.
Cumulative Argument: Deductive and Probabilistic Formulation
A cumulative argument consists of various yet converging proofs, where the aggregation of evidence brings the claim closer to being proven, even if each individual piece of evidence might not suffice on its own. “Cumulative” in this context means building up evidence sequentially to support the intended claim. In other words, when a conclusion cannot be proven by a single argument or piece of evidence due to its weaknesses, a stronger conclusion can be reached by considering the collective sum of all the evidence. This argument can be presented in both deductive and probabilistic formulations.
In a deductive argument, multiple arguments can be presented for a given attribute, resulting in justificatory overdetermination (for theism). When considering a probabilistic argument, Bayes’s theorem is commonly used. By combining numerous pieces of evidence, each providing some support to theism, the goal is to construct a case that significantly bolsters theism more effectively than any single argument could on its own. The cumulative argument can be evaluated on three levels:
1. Advantages and Strengths: Impact on Belief: While a single witness may not establish a belief, their testimony might challenge atheism or ignorance. Stabilizing Effect: The combined weight of cumulative evidence can reinforce believers’ faith.
2. Solvable Critiques: The cumulative argument is often seen as complex and impractical for the general public due to the necessity of collecting and analyzing diverse types of evidence, which requires philosophical training. This creates an accessibility problem, as most religious believers may not have the requisite background to benefit from such arguments. The question arises whether this argument is an effective way to defend theism to a general audience. The answer is that the general public can accept the epistemic justification from cumulative arguments with the support of philosophical experts, similar to how they accept scientific beliefs about phenomena like the existence of electrons. This method is common in the sciences, so it should be applicable to religious beliefs as well.
3. Critiques: a) In the deductive formulation of the cumulative argument, there is a linear relationship between the probability of a belief being correct and its degree of reasonableness. However, this formulation lacks a specific or objective standard for determining the threshold of reasonableness. b) The formulation of probabilities in cumulative reasoning emphasizes the multiplication of probabilities, but it does not assign specific values for this multiplication. This is considered a weakness in this approach.
Muslims Contributions
Islamic thought is not indifferent to the cumulative argument. Across various sciences, different versions or levels of argument accumulation have been proposed within the Islamic intellectual framework. Muslim thinkers have utilized this model not only in arguments for the existence of God but also in the broader methodology of beliefs. This indicates that contemporary theological debates in the Islamic intellectual space incorporate this pattern. Here are some examples demonstrating the presence and relevance of this pattern in Islamic thought:
Principles of Islamic Jurisprudence: A group of Islamic jurists employs an accumulation model known as “suspicion density” to deduce jurisprudential issues. This approach involves gathering evidence and aggregating weaker suspicions, which individually lack validity and authority, to reach a higher level of knowledge that meets the criteria for validity and authority. It is not feasible to use reasons whose falsity is evident in the inference process. However, reasons whose falsity has not been established, even if their likelihood is weak, can still be effective in the inference process. Although the inference resulting from suspicion density is not exactly an inductive method, it is based on induction; thus, the two are similar. In both methods, the acquired knowledge is gradually strengthened through repeated observations and accumulating evidence. Consequently, some Islamic jurists have utilized the principles of inductive logic to explain the quality and feasibility of suspicions.
Philosophy: Muslim philosophers aim for the epistemological position of truth and certainty, but often recognize that this is difficult to achieve due to human cognitive weaknesses, which vary among individuals. Some people can attain certain knowledge, while others cannot. Given this challenge, an epistemological question arises: What should be done when certainty cannot be reached? Muslim philosophers suggest focusing on the epistemological value of suspicion and persuasive reasons, which are evaluated according to people’s varying perceptive abilities. When certainty is unattainable, persuasive reasons can prevent doubt about the possibility of knowledge. Another key question is whether certainty can arise from multiple doubts. According to Muslim philosophers, doubt holds epistemological validity due to its varying intensity. Accumulating suspicions can eventually lead to certainty and belief in a particular issue. Therefore, cumulative suspicions, when sufficiently aggregated, can achieve a level of validity.
Theology: Some Islamic theologians have used the accumulation pattern to substantiate the truth of prophethood claims. Beyond relying on miracles, they have considered other methods, particularly the collection of evidence. These theologians assert that gathering evidence is a rational approach to discovering the truth, commonly used by researchers in social and natural sciences to achieve specific results. Although each piece of evidence may not be sufficient to conclusively prove prophethood, the combination of multiple pieces of evidence diminishes the likelihood of deception regarding the prophet’s divine claim.
Conclusion
Human epistemology seeks truth and certainty, but this is often hindered by individual perceptual weaknesses. This raises the question of what to do when certainty cannot be attained. Muslim and Western thinkers have developed frameworks focusing on the accumulation pattern and the epistemological value of suspicion and persuasive reasons, considering perceptual differences. In cases where certainty is unachievable, they use the accumulation of suspicion and persuasive reasons to avoid doubting the possibility of knowledge.