4. *But does it only cause this in the time of sickness, or preternatural disorder? Nay, but more or less, at all times, even in a state of perfect health. Let a man be ever so healthy, he will be more or less delirious, every four-and-twenty hours. For does he not _sleep_? And while he sleeps, is he not liable to _dream_? And who then is master of his own thoughts, or able to preserve the order and consistency of them? Who can then keep them fixt to any one point, or prevent their wandering from pole to pole? 5. *But suppose we are awake, are we always so awake, that we can steadily govern our thoughts? Are we not unavoidably exposed to contrary extremes, by the very nature of this machine, the body? Sometimes we are too _heavy_ too dull and languid, to pursue any chain of thought. Sometimes, on the other hand, we are too _lively_. The _imagination_, without leave, starts to and fro, and carries us away, hither and thither, whether we will or no: and all this, from the merely natural motion of the spirits, or vibration of the nerves. 6. *Farther, How many wanderings of thought may arise, from those various _associations_ of our ideas, which are made entirely without our knowledge, and independently on our choice? How these connexions are formed we cannot tell: but they are formed in a thousand different manners. Nor is it in the power of the wisest or holiest of men, to break those associations, or to prevent what is the necessary consequence of them, and matter of daily observation. Let the fire but touch one end of the train, and it immediately runs on to the other. 7. *Once more. Let us fix our attention as studiously as we are able on any subject, yet let either _pleasure or pain_ arise, especially if it be intense, and it will demand our immediate attention, and attach our thought to itself. It will interrupt the steadiest contemplation, and divert the mind from its favourite subject. 8. *These occasions of wandering thoughts lie within, are wrought into our very nature. But they will likewise naturally and necessarily arise, from the various impulse of _outward objects_. Whatever strikes upon the organ of sense, the eye or ear, will raise a perception in the mind. And accordingly, whatever we see or hear, will break in upon our former train of thought. Every man therefore that does any thing in our sight, or speaks any thing in our hearing, occasions our mind to wander more or less from the point it was thinking of before.