I have often posed this thought experiment in debates on the “free will” question, and rarely does anyone provide a coherent answer. The thought experiment is this : Firstly, imagine that you take a “free will decision” to do something (for example, you decide to have tea rather than coffee with your breakfast). And now imagine that the entire universe could be “reset” to a few moments before that “free will” decision, such that the properties of absolutely everything in the universe (including your internal brain states, desires, intentions, wishes, wants etc) are identical to the way they were the first time. And now you choose again. Would your choice necessarily be the same as it was the first time? If “yes”, then this is determinism pure and simple. If “no”, then what logical or rational explanation (apart from random or stochastic behaviour) could you possibly give for choosing differently?