Michael Frede argued that the modern notion of a free will was not present in the earliest Greek thinkers, but developed late in Stoicism, especially with Epictetus, and was refined by Augustine to become the modern notion.
Frede thus appears to agree with Susanne Bobzien, but it depends on the definition of “free will” and the “free will problem” that they are using.
Frede claims to have no preconception of free will. He hopes that it will emerge from a careful reading of the ancient works. In his 2011 book, A Free Will: Origins of the Notion in Ancient Thought, he says,
“Now, though I do not presuppose a specific notion of a free will, let alone want to endorse or advocate some specific notion of it, I do rely on something like a general idea of a free will, something like a schema which any specific notion of a free will or any particular version of the notion of a free will, at least in antiquity, will fit into. I do not arrive at this general idea or schema on the basis of some philosophical view as to what any notion of a free will has to look like but rather with the benefit of historical hindsight. That is to say, I have looked at the relevant ancient texts and have abstracted this schema from those texts which explicitly talk of a will, the freedom of the will, or a free will. In having such a schema, we shall at least have a general idea of what we are looking for when we investigate the origins of the notion of a free will but without having to commit ourselves to any particular view, ancient or modern, as to what a free will really is.” (pp.6-7)
Frede finds in the Stoics a notion of will that is distinguished from the Platonic or Aristotelian notions by denying any role for a nonrational element in the mind or soul.
“With Stoicism, then, we get for the first time a notion of the will as an ability of the mind or of reason to make choices and decisions. This ability, though, which we all share, in the case of each of us is formed and developed in different ways. How it develops is crucially a matter of the effort and care with which we ourselves develop this ability, which we also might neglect to do. The will thus formed and developed accounts for the different choices and decisions different human beings make. As we have seen, the precise form in which the Stoics conceive of the will depends on their denial of a nonrational part or parts of the soul. Hence in this specific form the notion of a will was unacceptable to Platonists and to Aristotelians, who continued to insist on a nonrational part of the soul.”