It is argued that the sensorium of God was introduced into the Quaestiones added to the end of Newton’s Optice (1706) as a way of answering objections that Newton had failed to provide a causal account of gravity in the Principia. The discussion of God’s sensorium indicated that gravity must be caused by God’s will. Newton did not leave it there, however, but went on to show how God’s will created active principles as secondary causes of gravity. There was nothing unusual in assuming that God, acting as the First Cause, operated in nature by means of secondary causes; but it was unusual to devote as much time to discussing God’s precise role as to discussing the secondary causes themselves. It is contended that Newton felt the need to do this to persuade readers that what might seem like a second cause that could not possibly work could be made to work by the omnipotent God.

Properly understood, the instrumental rule says to take means that actually suffice for my end, not, as is nearly universally assumed, to intend means that I believe are necessary for my end. This alternative explains everything the standard interpretation can—and more, including grounding certain correctness conditions for exercises of our will unexplained by the standard interpretation.

It is often claimed that libertarianism offers an unattractive conception of free will and moral responsibility because it renders free agency inexplicable and irrational. This essay aims, first, to show that the soundness of these objections turns on more basic disagreements concerning the ideals of free agency and, second, to develop and motivate a truly libertarian conception of the ideals of free agency. The central contention of the essay is that the heart of libertarians’ ideal of free agency is the ideal of agential fundamentality.