LET. XII. ARTIFICIAL DIVISIONS OF TIME. 199

“ From the succelllon of our own ideas, andfrom the successive variations of external objectsin the course of nature, we easily acquire theideas of duration and time, and of their mea-sures. We conceive true or absolute time, toflow uniformly in an unchangeable course, whichalone serves to measure with exactness thechanges of all other things. For unless we cor-rect the vulgar measures of time, which aregross and inaccurate, by proper equations, theconclusions are always found to be incorrect anderroneous. Time may be conceived to be di-vided into successive parts that may be less andless without end, though, with respect to anyone particular being, there may be a least sensi-ble time, as well as a minimumsensibile in othermagnitudes, JBut however various the flux oftime may appear to different intellectual beings,it cannot be thought to depend upon the ideasof any created being whatever.”

Time is in a perpetual flux, and perishing;but a representation of it is preserved in thespace described by motion. As the fun, there-fore, is the most conspicuous body in our system,and appears to move regularly through the hea-vens, his motion is naturally fixed upon as oneof the properest measures of time that is affordedUs by nature. It is by means of his apparentdiurnal and annual revolutions, that we obtainshe two grand divisions of time, into days andO 4 years;