Recently I have been trying to understand how a logical, rational case can be made for the existence of the immaterial rational human soul, so I was wondering if anyone on this forum has any suggestions for accomplishing this. Intellect, along with will, are two of the proposed functions of the rational soul. Higher order reasoning and willing are usually attributed to more complex neurochemical processes in the human brain. Despite this, I think a case can be made for the existence of the rational soul via an argument for the immateriality of human intellect. The argument is as follows: (source: edwardfeser.blogspot.com/2011/01/against-neurobabble.html)
Humans are able to think in terms of abstract universal concepts. Consider a simple example (made in the above article): triangularity. Triangularity is a concept that cannot be explained by a materialist paradigm alone. For instance, someone may draw a triangle but this is not sufficient to express triangularity, as an instantiation of triangularity would necessarily have features that the concept lacks (such as a triangle being scalene which is not a feature of triangularity, a 2D shape is also a feature the concept lacks). One may argue that there is a common neurochemical signal that, although difficult to identify, nonetheless exists when a human thinker considers triangularity. But what would the signal be? Everybody reading this post probably is imagining something different. The thinker may not even be thinking of an image, but maybe instead is thinking of the word or the sound of the word. Is the word “triangularity” the commonality? Not really, because is it in English, Spanish, French, Italian, Japanese, Greek, Latin, pig Latin, clingon, some weird language only understood by the thinker? Since the mental imagery or physical sensation is indeterminate, it stands to reason that there is an immaterial component to human intellect that is able to understand these concepts. The universal concept would then be determinate. Once the concept is grasped and understood it cannot mean anything else.
Consider another example where there is no pre-existing human bias. Suppose astronauts land on Mars and discover the following scrawled on the side of a mountain: “&&#(J%^^,@**###$+>><.” It’s obviously the result of an intelligent agent and not random processes but is the preceeding character string sufficient for understanding what it means?
Corrections and criticisms are welcome