It's not insane to deny free will

It is possible to make the claim that 'we exist if we have free will' and that by extension to deny the truth of free will is to deny our very existence. But this might not be the case and the reality might be more nuanced. A lack of free will doesn't necessarily mean that a thing does not exist... determinists are often willing to accept that they exist... their only claim is that they have no free will. If we take the hypothetical example of a plain rock having no free will... clearly we are not at the same time denying that the rock exists. The determinist is only making the claim that they and the rock are similar and that they have no special differences as far as choice and free will are concerned. It can be argued that people (and things) will always make their best choice and so that even when we have the perception of making a choice all that is happening is that we are deducing our best action based on the information and knowledge available. It is not a choice because there is no active agent involved in the process it is simply a weighing of the evidence in favour of that which is best for the individual. If we are always certain to make our best decision then it becomes difficult to claim that a 'choice' is being made... when all that is happening is that someone is coming to their (objectively) best decision given the evidence. This process might have the appearance of free will but all that is happening is that we are observing the process of a person analysing this data. Even if we choose and have choices this doesn't mean we have free will. We might have no option but to choose the best option. Few people reject success.