MIND AND SOUL But human beings, like all agents, Wnite or inWnite, need a reason for acting; that follows from the principle of suYcient reason In the case of free agents, Leibniz maintains, the motives that provide the suYcient reason for action ‘incline but not necessitate’ But it is hard to see how he can really make room for a special kind of freedom for human beings True, in his system, no agent of any kind is acted on from outside; all are completely self-determining But no agent, rational or not, can step outside the life-history laid out for it in the pre-established harmony Hence it seems that Leibniz cannot consistently accept that we enjoy the liberty of indiVerence that he described in the Discourse All that is left is ‘liberty of spontaneity’—the ability to act upon one’s motives But this, as Bramhall had argued against Hobbes, is an illusory freedom unless accompanied by liberty of indiVerence Berkeley and Hume on Spirits and Selves In the universe of Berkeley there are only two kinds of things: spirits and ideas ‘The former’, he says, ‘are active, indivisible substances; the latter are inert, Xeeting, dependent beings, which subsist not by themselves, but are supported by, or exist in minds or spiritual substances’ (BPW, 98) Since Berkeley’s metaphysical system places more weight on the notion of spirit than any other philosophy, one would expect that he would give us a full account of the concept; but in fact his philosophy of mind is remarkable jejune Indeed, he tells us that we have no idea of what a spirit is This turns out to be less agnostic than it sounds, because Berkeley is here, as so often, using ‘idea’ to mean image He concedes that we have a notion of spirit in the sense that we understand the meaning of the word A spirit is a real thing, which is neither an idea nor like an idea, but ‘that which perceives ideas, and wills and reasons about them’ (BPW, 120) Perhaps, for consistency, Berkeley should have said that a spirit was a congeries of ideas, just as he said a body was; but in the case of spirit, unlike body, he is willing to accept the notion of an underlying substance, distinct from ideas, in which ideas inhere There is no distinction, in Berkeley’s philosophy, between ‘spirit’ and ‘mind’; he simply prefers the Wrst term because it emphasizes the mind’s immateriality 235