Locke's compatibilism: Suspension of desire or suspension of determinism?

In Book II, chapter xxi of the Essay Concerning Human Understanding, on ‘Power’, Locke presents a radical critique of free will. This is the longest chapter in the Essay, and it is a difficult one, not least since Locke revised it four times without always taking care to ensure that every part cohered with the rest. My interest is to work out a coherent statement of what would today be termed ‘compatibilism’ from this text – namely, a doctrine which seeks to render free will and determinism compatible. By emphasizing the hedonistic dimension of his argument, according to which we are determined by “the most pressing uneasiness” we feel, I show how a deterministic reading is possible. This was seen by Locke’s favorite and also most radical disciple, the deist Anthony Collins, whose treatise A Philosophical Inquiry Concerning Human Liberty (1717) is both a critique of Essay II.xxi and a radicalization of its contents. I argue that Collins articulated a form of determinism which recognizes the specificity of action, thanks in large part to the uniquely ‘volitional’ determinism suggested by Locke