I am aware of the fine tuning argument.Its not my favorite but is well supported by some scientists who happen to be believers. I don't think that the fine tuning argument uses special pleading, its not an argument that ignores all unfavorable evidence. I am curious, why use the word 'irrational' to express the point you are attempting to make? Its confrontational and misleading (if you are using the common definition).
I'll try to bring you up to speed a bit. The term "irrational" in general usage is defined as something akin to "incoherent" and some add something like "or inconsistent with reality" (externally consistent with what is known to be true).
Some here have argued that there is some (as of yet unknown) definition of "irrational" that would apply to belief in a god but not to other beliefs such as extra terrestrial intelligent life. I, Beth, cj.23 and some others have been skeptical that such a definition exists without resorting to special pleading (as in "rational - any coherent belief except for belief in a god").
In the course of the discussion, comparisons were made between beliefs in a god and other beliefs (aliens, teapots orbiting Jupiter, etc) in order to determine whether or not a valid distinction could be made to label belief in a god necessarily irrational but other beliefs (particularly other beliefs for which there is no compelling evidence) rational.
cj.23 at one point posted a logical Bayesian argument (i.e. one that uses Bayes theorem) for the existence of a god based on evidence of fine-tuning. This was compared to a hypothetical logical argument for aliens based on the Drake equation to see if a valid difference could be found.
So...given your background you might agree that there is probably not a definition of "irrational" that would allow belief in a god to be considered "irrational" without also marking other beliefs commonly held to be "rational" to be "irrational" (without resorting to special pleading). You might not agree as to whether the belief in a god is actually unsupported by compelling evidence -- I personally don't think it is, but I don't think it's necessary for it to be in order to be rational as long as it's not incoherent or inconsistent with reality.
So, you said that there is compelling evidence (in the form of logical arguments rather than empirical observation, I assume) of a god (presumably the Christian God, although I'd be fine with it being any god). I'm interested in knowing what you feel is the most compelling of these types of arguments. The fine-tuning one is based on some premises that are unsupported by compelling evidence, which makes the conclusion less than compelling (as would be an argument for aliens based on Drake's equation). Do you know of an argument that has stronger premises?
Anyway, my favorite logical and reasonable arguments for the existence of God are the KCA as expressed by William Craig ThD PhD. Its a first cause argument. BTW there are 20 (!) arguments for the existence of god that are considered worthy of professional 'academic' consideration.
Can you post a link to the one that you feel is the most compelling (what is "KCA")? Also, if you have a link to a reference to the 20 arguments of which you speak that might be interesting as well. Thanks!
-Bri
Last edited: