William King was an older contemporary of Samuel Clarke and perhaps was an even stronger libertarian than Clarke. A third British philosopher working at the same time was the determinist thinker Anthony Collins. In those days, the argument between free will and determinism was described as the problem of liberty versus necessity. Some philosophers, including King, distinguished between physical and moral necessity. Others did not. Following Thomas Hobbes, liberty (or freedom) was defined as being free from external compulsion, what today we call freedom of action. This left human choices (King called them Elections), to be determined by necessity (either or both moral and physical).
King and his contemporaries all influenced the thinking of David Hume (1711-1776), and perhaps most important to understand how they framed the problem of free will, they all shared a strong belief in an almighty God, which Hume would later de-emphasize in favor of If there be any thing obscure and difficult in Philosophy, we are sure to find it in that part which treats of Elections and Liberty. There is no point about which the learned are less consistent with themselves, or more divided from each other. Nor is it an easy matter to understand them, or to give a certain and true representation of their opinions. I think they may be distinguished into two sects, both admitting of liberty, the one from external compulsion, but not from internal necessity; the other from both. Naturalism. Compared to the presumably infinite God, men are described by King as finite and limited in their ability to know.
Since man (nay every created being) is necessarily of a limited nature, it is plain that he cannot know every thing. The most perfect creatures therefore are ignorant of many things: nor can they attain to any other knowledge than what is agreeable to their nature and condition. Innumerable truths therefore lie hid from every created understanding: for perfect and infinite knowledge belongs to God alone; and it must be determined by his pleasure what degree every one is to be endowed with: for he only knows the nature and necessity of each, and has given what is agreeable thereto.King and Clarke strongly opposed the atheistic materialism popularized by Thomas Hobbes a generation earlier, despite Clarke's enthusiasm for the deterministic physics of his close friend Isaac Newton. Like Clarke, King defends against the charge that the final determination of the will, after consideration of the alternative possibilities, implies strict necessity.
But as to the actions of the will itself, namely to will, or to suspend the act of volition, they think that it is determined to these, not by itself, for that is impossible; but from without. If you ask from whence? They answer, from the pleasure or uneasiness perceived by the understanding or the senses; but rather, as they imagine, from the present or most urgent uneasiness: since, therefore, these are produced in us ab extra, not from the will itself, and are not in its power, but arise from the very things themselves; it is manifest, according to these men, that we are not free (at least from necessity) to will or not to will, that is, with regard to the immediate acts of the will.King clearly defines the act of self-determination, making a choice (Election) that was not determined before the choice is made. Election is an act of determination (pp. 229-230). An agent is "self-active," he says, capable of being determined by itself alone.
when any thing is proposed to be done immediately, it must necessarily be; but when either of them is done, the power is determined by that very act: and no less force is requisite to suspend than to exert the act, as common sense and experience may inform any one.