Liberty of spontaneity involves an agent being able to act according to her own willings and desires, unhindered by external obstacles which might constrain or restrict her conduct (e.g., the walls or bars of a prison [T 2.3.1.17/406]). This kind of liberty does not imply an absence of causation and necessity, unless we incorrectly assume that what is caused is somehow compelled or forced to occur. In the Enquiry Hume drops the distinction between two kinds of liberty and instead provides an account of what he calls “hypothetical liberty” (EU 8.23/95). A liberty of this kind involves “a power of acting or not acting, according to the determinations of the will; that is, if we choose to remain at rest, we may; if we choose to move, we also may.” According to Hume this sort of hypothetical liberty is “universally allowed to belong to every one, who is not a prisoner and in chains” (ibid.). Although Hume is committed to the existence of both liberty of spontaneity and hypothetical liberty, they are not the same. A person may enjoy liberty of spontaneity and act according to the determinations of her own will, and still lack hypothetical liberty. If she chose otherwise her action might still be obstructed (e.g., as with a person who chooses to remain in a room but could not leave if she chose to because the door is locked).