The supposition that there is some further power or energy in matter, whereby causes somehow compel or force their effects to occur, is the fundamental source of confusion on this issue. It is this that encourages us to reject the suggestion that our actions are subject to necessity on the ground that this would imply some kind of violence or constraint – something that would be incompatible with liberty of spontaneity. When confusions of this sort are removed, all that remains is the verbal quibble about using the term “necessity” – which is not itself a substantial point of disagreement.