Rebecca Stark looks at the expression 'author of sin', finding that many who use it don't really have a clear idea what they mean, and once they clarify it what they're saying may not follow. I think she's expressing thoughts I've had for a long time but haven't really been able to express well. One line struck me:
Somehow, for those who argue that it's the purposeful nature of God's permission of sin that makes him the author of sin, a supreme being who permits sin for no reason is better than one who permits it for a reason. When it comes to the permission of sin, in their view, arbitrary is better than purposeful.
This is something that has always seemed strange to me about certain Arminian/libertarian responses to the problem of evil (especially in their open theistic form but sometimes even in more standard libertarian views that don't necessarily imply open theism, e.g. some of Peter van Inwagen's work). I can't understand how having no reason for something is supposed to be better than having a really good reason for doing or allowing it. But this is commonly trotted out as a better defense of how God would allow evil than the traditional view that God really does have good reasons for allowing evil