T 2.3.8.12

In our common way of thinking we are plac'd in a kind of middle station betwixt the past and future; and as our imagination finds a kind of difficulty in running along the former, and a facility in following the course of the latter, the difficulty conveys the notion of ascent, and the facility of the contrary. Hence we imagine our ancestors to be, in a manner, mounted above us, and our posterity to lie below us. Our fancy arrives not at the one without effort, but easily reaches the other: Which effort weakens the conception, where the distance is small; but enlarges and elevates the imagination, when attended with a suitable object. As on the other hand, the facility assists the fancy in a small removal, but takes off from its force when it contemplates any considerable distance.