From Against Calvinism:

Virtually all Calvinists (as distinct from some in the Reformed tradition and especially what I have called “revisionist Reformed” theologians) affirm a strong or high view of God’s sovereignty such as Boettner’s. Did Calvin himself affirm such? In Calvin’s Institutes of the Christian Religion, Geneva’s chief pastor wrote about God’s providence: “We ought undoubtedly to hold that whatever changes are discerned in the world are produced from the secret stirring of God’s hand … what God has determined must necessarily so take place.” 3 The surrounding context, including a vivid illustration about a merchant robbed and killed by thieves, makes absolutely clear that Calvin believed nothing at all can happen that is not foreordained and rendered certain by God. He says that a Christian will realize that nothing is truly an accident, as everything is planned by God.