Book Review: How Reason Can Lead to God by Joshua Rasmussen


How Reason Can Lead to God is a book for the careful thinker. This is not a book that sets out to prove a stated conclusion. Instead, Joshua Rasmussen starts with a simple premise: something exists. From there, he carefully walks through a series of steps, ultimately demonstrating that in order to explain the fact that something exists we must posit the existence of God. Of importance is that each step outlined by Rasmussen is based on his own truth-seeking journey, and all he asks of the reader is the willingness to follow reason wherever it leads.


Rasmussen invites the reader to imagine building what he calls, “a bridge of reason,” constructed only using the tools of logic. The first step of this building project is to acknowledge that something exists. For the moment, it doesn’t matter what that something is. The next step is to recognize that that something is part of everything that exists. Here we have problem. Whenever we explain the existence of something, we point to something else outside of it as the explanation. But this won’t work as the explanation of everything since, by definition, nothing exists that is not part of everything already.

The solution, Rasmussen proposes, is that the world has within it a foundation that provides the explanation of the existence of everything else. In order for this to work, this foundation must have two characteristics: an independent nature and a necessary nature. Only if the foundation has an independent nature can it truly explain the totality of everything else since all else has a dependent nature. Furthermore, this foundation can have an independent nature because it has a necessary nature.

Next, Rasmussen puts this proposal to the test by addressing nine separate objections can be raised against such a foundation. What about the option of an infinite regress? Doesn’t this foundation argument commit the fallacy of composition? Don’t virtual particles disprove the need for an explanation? These are just a few of the responses that Rasmussen addresses, and in each case, he shows how the objection misses the mark.

Moving on, Rasmussen explores some more characteristics of this foundation. In addition to being independent and necessary, it must also be eternally powerful. That is, it must have within it the capacity to produce an effect, and it must have this capacity eternally. This follows logically from the fact that the independence and necessity of the foundation.

Using the tools of simplicity, explanatory depth, and uniformity, Rasmussen shows how the foundation itself must be “purely actual.” The simpler the hypothesis, the more internally probable it is. The more the hypothesis can explain, the better it is. Uniformity allows us to see how the foundation is set apart from all other things since all other explanations are uniformly dependent on outside explanations.

Rasmussen now shifts the focus from attributes of the foundation to the connection between the foundation and various aspects of the world. He begins with the connection to minds. Minds cannot be accounted for on materialist explanations because materialism fails to provide the foundation for qualia (the ways sensations feel), the direct access we have to our experiences, and free will. Therefore, the foundation must also provide for the existence of mental properties such as thoughts and intentions.

Next, Rasmussen turns to the question of what could provide for the foundation of matter. He addresses various proposals, including chance, the anthropic principle, appeals to further physics, the multiverse, and many others. Ultimately, he demonstrates that all proposals are found wanting with the exception of appealing to a foundational mind which has the ability to form intentions.

With mind and matter out of the way, Rasmussen turns to explain the foundation of morals. He begins his assessment by proposing a tool: the ability to sense moral goodness. This tool is not perfect, but it allows us to distinguish between at least some good and bad things. These are not just subjective opinions, rather, they are true windows into actual goodness. This notion is debated. Thankfully, Rasmussen carefully addresses several objections to this Moral Window Hypothesis. In order to explain both the existence of moral principles and the discoverability of those principles, the foundation itself must have a moral nature.

The final aspect that Rasmussen explores is how the foundation of everything functions to explain all reasoning. He begins by showing how the foundation of everything explains mathematics. Mathematics can best be explained by the existence of a mind-like foundation. Similarly, the principles of reason, which ultimately outline how people think correctly, are best explained by a mental foundation of reality.

Now that all the aspects of the foundation are in place, Rasmussen illuminates this foundation by outlining how it is perfect. To do this, he uses the notion of pure actuality discussed in an earlier section of the book. If the foundation is to be perfect, it must be the most valuable thing in existence. If the foundation is purely actual, then it follows that it has no limits when it comes to value, and therefore the foundation must be maximally valuable. Similarly, the foundation must be maximally powerful and maximally knowledgeable.

With the bridge of reason completed, Rasmussen engages with major challenges to the suggestion that the world has an underlying foundation. The first challenge, regarding the problem of evil and suffering, is discussed at length. Following his pattern, he responds with reason. He concludes that it is entirely possible that a perfect mind could have good reasons for creating a world that is morally interesting, which includes the presence of evil. By contrast, it is not clear that the creatures would have knowledge of these reasons.

Next, Rasmussen replies to eight additional challenges by explaining how he, personally, navigates them. These challenges cover a wide variety of topics, including but not limited to: hell, the silence of God, blind faith, miracles, and others. While the answers are brief, they provide examples of how at least the author has been able to satisfy his own concerns. The reader is free to accept these answers or not, but at a minimum, he or she should have a starting point and some encouragement to continue seeking more satisfactory answers to these questions, as well as any others that arise.

Rasmussen concludes the book by presenting what he calls the Argument from Limits. The argument is fairly technical, but the end result is that perfection itself points to its own possibility, and furthermore to its own necessity. This is unique among all properties, and ultimately, if successful, demonstrates that all properties of everything that exists points to the existence of God.

Final Thoughts

The importance of How Reason Can Lead to God in the world of apologetics cannot be overstated. Rasmussen has successfully presented an argument of the highest degree of technical rigor in a manner that is accessible to the layman. Every Christian should not only learn the overall argument of Rasmussen’s book, but should also learn the intellectual humility that he exhibits has he engages in an honest pursuit of truth with nothing more than reason as his guide. But it is written with the skeptic in mind, and therefore, in addition to sitting on the apologist’s shelf it ought to make its way into the hands of the skeptics everywhere.

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