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our minds, beyond which they can neither delay nor hasten.
9. 10. The reason I have for this odd conjecture, is from observing that in the impressions made upon any of our senses, we can but to a certain degree perceive any succession; which, if exceeding quick, the sense of succession is lost, even in cases where it is evident that there is a real succession. Let a cannon-bullet pass through a roon, and in its way take with it any limb, or fleshy parts of a man; it is as clear as any demonstration can be, that it must strike successively the two sides of the room. It is also evident, that it must touch one part of the flesh first, and another after, and so in succession : And yet I believe no-body, who ever felt the pain of such a shot, or heard the blow against the two distant walls, could perceive any succession cither in the pain or sound of so swift a stroke. Such a part of duration as this, wherein we perceive no succession, is that which we call an instant, and is that which takes up the time of only one idea in our minds, without the succession of another, wherein therefore we perceive no succession at all.
§. 11. This also happens, where the motion is so slow, as not to supply a constant train of fresh ideas to the senses, as fast as the mind is capable of receiving new ones into it; and so other ideas of our own thoughts, having room to come into our minds, between those offered to our senses by the moving body, there the sense of motion is lost; and the body, though it really moves, yet not changing perceivable distance with some other bodies, as fast as the ideas of our own Binds do naturally follow one another in train, the thing seems to stand still, as is evident in the hands of elocks and shadows of sun-dials, and other constant but slow motions; where, though after certain intervals, we perceive by the change of distance that it hath moved, yet the motion itself we perceive not.
9. 12. So that to me it seems, that the This train constant and regular succession of ideas in a the measure Waking inan is, as it were, the measure and of vrher sucstandard of all other successions : whereof Cessions.
if any one either exceeds the pace.of our. ideas, as where
§. 13. If it be so that the ideas of our cannot fix minds, whilst we have any there, do con, long on one stantly change and shift in a continual suc: invariable cession, it would be impossible, may any jdede .. one say, for a man to think long of any one thing. By which, if it be mcant, that a man may have one self-same single idea a long time alone in his mind, without any variation at all, I think, in matter of fact, it is not possible; for which (not knowing how the ideas of our minds are framed, of what materials they are made, whence they have their light, and how they come to maķe their appearances) I can give no other reason but experience: And I would have any one try whether he can keep one unvaried single idea in his mind, without any other,' for any considerable time
§. 14. For trial, let him take any figure, any degree of light or whiteness, or what other he pleases; and he vill, I suppose, find it difficult to keep all other ideas out of his mind : But that some, either of another kind, or various considerations of that idea (each of which considerations is a new idea) will constantly succeed one another in his thoughts, let him be as wary as he can.
$. 15. All that is in a man's power in this case, think, is only to mind and observe what the ideas are that take their turns in his understanding; or else to direct the sort, and call in such as he hath a desire On use of: but hinder the constant succession of fresh ones, I think, he cannot, though he may commonly choose whether he will heedfully observe and consider them.
$. 16. Wliether these several ideas in a lese man's inind be made by certain motions, ever made, I will not here dispute : but this I am sure, include no that they include no idea of motion in their sense of mo, appearance; and if a inan had not the idea 40. of motion otherwise, I think he would have none at all: which is enough to my present purpose, and suthiciently shows, that the notice we take of the ideas of our own minds, appearing there one after another, is that which gives us the idea of succession and duration, without which we should have no such ideas at all. It is not then motion, but the constant train of ideas in our minds, whilst we are waking, that furnishes us with the idea of duration : whereof motion no otherwise gives us any perception, than as it causes in our minds a constant succession of ideas, as I have before showed : And we have as clear au idea of succesion and duration, by the train of other ideas succeeding one another iny our minds, without the idea of any motion, as by the train of ideas caused by the uninterrupted sensible change of distance between two bodies, which we have from motion; and therefore we should as well have the idea of duration, were there no sense of motion at all.
$. 17. Having thus got the idea of duration, the next thing natural for the mind Time is du.
ration set out in bi to do, is to get some measure of this com- by measures De Lis non duration, whereby it might judge of
its different lengths, and consider the distinct order wherein several things exist, without which a great part of our knowledge would be confused, and a great part of history be rendered very useless. This consideration of duration, as set out by certain periods, and marked by
certain measures or epochs, is that, I think, which most el properly we call time,
. 18. In the measuring of extension, er there is nothing more required but the ap- sure of time
plication of the standard or measure we must divide make use of to the thing; of whose exten- its whole due sion we would be informed. But in the
equal periods. measuring of duration, this cannot be done, because no two different parts of succession can be put
together to measure one another : and nothing being a
beginning of nature, constant, regular, and
• universally observable by all mankind, and micasures of supposed equal to one another, have been
with reason made use of for the measure of duration. But the distinction of days and years having depended on the motion of the sun, it has brought this mistake with it, that it has been thought that motion and duration were the measure one of another: for men, in the measuring of the length of time, having been accustomed to the ideas of minutes, hours, days, inonths, years, &c. which they found themselves upon any mention of time or duration presently to think on, all which portions of time were measured out by the motion of those heavenly bodies: they were apt to confound time and motion, or at least to think that they had a necessary connexion one with another: whereas any constant periodical appearance, or alteration of ideas in seemingly equidistant spaces of duration, if constant and universally observable, would have as well distinguished the intervals of time, as those that have been made use of. For supposing the sun, which some have taken to be a fire, had been lighted up at the same distance of time that it now every day comes about to the sane meridian, and then gone out again
in their years by, ances.
about twelve hours after, and that in the space of an annual revolution, it had sensibly increased in brightness and heat, and so decreased again ; would not such regular appearances serve to measure out the distances of duration to all that could observe it, as well without as with motion? For if the appearances were constant, universally observable, and in equidistant periods, they would serve mankind for measure of time as well, were the motion away. .
$. 20. For the freezing of water, or the But not by blowing of a plant, returning at equidis- their motion, tant periods in all parts of the earth, would but periodias well serve me! to reckon their vears bv. - can appease as the motions of the sun: and in effect we see, that some people in America counted their years by the coming of certain birds amongst them at their certain seasons, and leaving thein at others. For a tit of an ague, the sense of hunger or tlıirst, a smell or a taste, or any other idea returning constantly at equidistant periods, and making itself universally be taken notice of, would not fail to measure out the course of succession, and distinguish the distances of time. Thus we see that men borą blind count time well enough by years, whose revolutions yet they cannot distinguish by motions, that they perceive not; and I ask whether à blind man, who distinguished his years either by the heat of summer, or cold of winter; by the smell of any flower of the spring, or taste of any fruit of the autumn; would not have a better measure of time than the Romans had before the retorination of their calendar by Julius Cæsar, or many other people, whose years, notwithstanding the motion of the sun, which they pretend to make use of, are very irregular? And it adds no small difficulty to chronology, that the exact lengths of the years that several nations counted by, are hard to be known, they differing very much one from ano. ther, and I think I may say all of them from the precise inotion of the sun. And if the sun moved from the
creation to the flood constantly in the equator, and so heks equally dispersed its light and heat to all the habitable Gal parts of the earth, in days all of the same length, with