Related Fallacies: Begging the question
Calvinists often pose questions along the lines of, “If 2 people are given the same grace, why does one receives it and another reject it?” This question was popularized on the internet by John Hendryx at monergism.com, who in one rendition of this particular fallacy states: “If prevenient grace places us in a neutral state, then what motivates one man to believe and not another? … What principle in him made him choose what he did?” [A Prayer That a Synergist Won’t Pray (An Open Challenge to All Synergists), John Hendryx]
Hendryx’s wording is very telling, he asks ‘what made him choose?’, when the defining property of a libertarian decision is that nothing caused it to be one way or another except the person’s own will. While free will certainly is subject to influence, if some external principle coerced, impelled, or simply necessitated a specific decision, then the choice could no longer be called ‘libertarian.’
To break down Hendryx’s question:
The context (note the title I listed above) is that Hendryx is addressing the question to Synergists (people like myself who believe that there are at least some non-necessitated choices), trying to show what he perceives as problems in our beliefs. His putting forth of the question, “What principle in him made him choose what he did?”, amounts to him asking what necessitates our decisions, since anything that makes someone choose a specific way would constitute necessitation of that choice.
So given that,
1. The question is posed to people who believe in libertarian (non-necessitated) decisions
2. The question challenges the libertarian view by asking what necessitates peoples’ specific choices
Hendryx’s question effectively boils down to him asking,
“What necessitates choices that aren’t necessitated?”
This line of questioning is not only logically absurd, but also requires assuming that all of our decisions must be necessitated, when that is in fact the proposition he is trying to prove. This fallacy is more formally known as ‘begging the question,’ a form of circular reasoning.
Calvinistic apologists often employ such fallacies in attempts to prove that libertarian free will is nonsensical, but looking to God as an example of how the will functions, we can see that a being with a free will can make choices without them being necessitated by something outside of its own will. For example, there was no principle in God that impelled Him to save anyone, but He chose to anyway. If God is truly free, then it’s absurd to argue that there are conceptual problems with the very idea of free will, and hence no tenable logical basis to argue that it couldn’t exist in human beings.