“Free will” is said in very many ways.
Philo of Alexandria (b. 25 BCE) is the earliest theologian to explicitly defend a radical concept of choice by the human, though he has no explicit concept of will as a separate faculty. While he borrows some philosophical terms, he writes mainly as an allegorical interpreter of the Septuagint (Greek translation of the Hebrew Torah). My account here is based on secondary sources.
For Philo, assent (synkatathesis) and choice (prohairesis) are exercised by the human as a whole, or by the human mind or soul as a whole. The possibility of human freedom or self-mastery (autexousia) stems from the human’s being created in the image of God. It can easily be lost, if we give assent to the passions. The sage (sophos) realizes her freedom by actively refusing such assent, while at the same time recognizing the nothingness (oudeneia) of herself and all creation, when taken apart from the Creator. But human choice in general is already exempt from material necessity.
Philo is sometimes presented as a reconciler of revelation with reason and philosophy, but for him the priority of revelation is absolute. He claims that virtue depends on faith in revelation; that Moses is the first and greatest of all philosophers; and that whatever is true in Greek philosophy is taken — indeed “plagiarized” — from Moses. His ideas apparently had little influence within Judaism until many centuries later, but they were vigorously taken up and developed by the early Christian church fathers.
Philo is the earliest identifiable advocate of what I have called strong omnipotence. But like Augustine later on, he insists at the same time that God is good, and that humans bear the entire responsibility for the existence of sin.
