To start, I do not believe that theists (or anyone at all for that matter) can claim that humans possess the property of aseity. First, there are just too many obvious examples of humans existing contingently. — Raymond Rider
First, to exist with aseity is not to exist of necessity. It is to exist uncaused. That is, it is to exist, yet not to have been created. If a person exists of necessity, then they would exist with aseity. But it does not follow that if someone exists with aseity, then they exist of necessity.
Second, I did not claim that 'humans' have this property, for humans are a composite of immaterial mind and sensible body. It is our sensible bodies that have come into being. Our immaterial minds have not.
I would need to hear an argument from someone about why a theist should believe in pre-existent souls, as I think it is rather counterintuitive to think that I existed before I showed up on earth. — Raymond Rider
It is not counterintuitive, rather it simply contradicts a conventional view about when we started to exist. In this thread antinatalism and theism are both taken for granted. And our self-existence is implied by these two views. For if antinatalism is true, then God has not created us. Furthermore, God would not permit anyone else to create us. Thus, as we exist we can conclude that we exist uncreated - that is, we exist with aseity.
But there are other arguments for our self-existence. For instance, we are indivisible. That is, we have a no parts (one cannot have half a mind). Sensible objects - such as our bodies - are divisible. Thus we are not our bodies. And simple things - things without parts - are not of a sort that can be created, for there is nothing from which one can create them. Thus, we exist with aseity (and are not our sensible bodies).
Finally, we have free will and are morally responsible for what we do. We would not have free will and would not be morally responsible for anything we did if everything about us traced to external causes. if we have ever come into being then everything about us would trace to external causes. Thus we have not come into being (and thus we exist with aseity).
The aseity thesis is, then, not counter-intuitive at all, for it follows from some apparent self-evident truths about us. It is unconventional, that's all. But philosophy is not about vindicating conventional views, is it?
Second, I think that affirming that there are things which possess the property of aseity apart from God causes a few problems for theism. This would involve the denial of God's ontological priority, an important good-making property. If there are things which exist in and of themselves apart from God, then God is not ontologically prior to those things. Thus, this would require us to believe that God is not perfect, as he lacks a good-making property. — Raymond Rider
I use the term God to denote a person who is omnipotent, omniscient and omnibenevolent. That's an orthodox use of the term (it's standard in philosophy to take the term to denote such a being). If someone wants to pack more into the term than that, then they are simply not talking about what I am talking about when I use the term. (They are free to do so - let's not get into a pointless discussion over how a word is used - it's just that it is not how I am using the word). Ontological priority just means 'existing before other things' and yes, I deny God exists before us. We all exist with aseity. But that is entirely consistent with God having the properties of omnipotence, omniscience and omnibenevolence.
You say lacking ontological priority would be a defect - how? I'll tell you what would be a defect: being the creators of us. We are ignorant bad people. You think a morally perfect, all powerful all knowing person would create creatures like us? That - that - would be a defect. Far from presenting any problem for theism, our self-existence shows just how an omnipotent, omniscient, omnibenevolent being's existence is entirely consistent with our own and explains why we are living here, in ignorance, in a dangerous world. My thesis generates no problems. It is the thesis that we are God's creations - a thesis that religious people subscribe to for dogmatic reasons and that enjoys no support from reasoned-reflection - that generates problems.