_Hotspur._ I will; that’s flat: He said, he would not ransom Mortimer: Forbad my tongue to speak of Mortimer: But I will find him when he lies asleep, And in his ear I’ll holla _Mortimer_! Nay, I will have a starling taught to speak Nothing but _Mortimer_, and give it him, To keep his anger still in motion. _Worcester._ Hear you, cousin, a word. _Hotspur._ All studies here I solemnly defy, Save how to gall and pinch this Bolingbroke: And that same sword-and-buckler Prince of Wales, (But that I think his father loves him not, And would be glad he met with some mischance), I’d have him poison’d with a pot of ale. _Worcester._ Farewel, my kinsman, I will talk to you, When you are better temper’d to attend. _First part, Henry_ IV. _act 1. sc. 4._ Having viewed a train of perceptions as directed by nature, and the variations it is susceptible of from different necessary causes, we proceed to examine how far it is subjected to will; for that will hath some influence, more or less, is observed above. And first, the rate of succession may be retarded by insisting upon one object, and propelled by dismissing another before its time. But such voluntary mutations in the natural course of succession, have limits that cannot be extended by the most painful efforts. The mind circumscribed in its capacity, cannot, at the same instant, admit many perceptions; and when replete, it has no place for new perceptions till others be removed. For this reason, a voluntary change of perceptions cannot be instantaneous; and the time it requires sets bounds to the velocity of succession. On the other hand, the power we have to arrest a flying perception, is equally limited. The longer we detain any perception, the more difficulty we find in the operation; till, the difficulty becoming unsurmountable, we are forced to quit our hold, and to permit the train to take its usual course. The power we have over this train as to uniformity and variety, is in some cases very great, in others very little. A train so far as composed of external objects, depends entirely on the place we occupy, and admits not more or less variety but by change of place. A train composed of ideas of memmory, is still less under our power. Objects which are connected, afford the mind an easy passage from one to another. They suggest each other in idea by the same means; and we cannot at will call up any idea that is not connected with the train[94]. But a train of ideas suggested by reading, may be varied at will, provided we have books in store.