We say of a thing that it is in the present when we have a precise perception of it.

We say that it is in the past when we preserve but an indistinct image of it.

A thing may have been accomplished millions of years ago, yet if it makes the strongest possible impression upon us it will not be for us a thing of the past; it will be present.

The order in which things revolve in the depths of the universe is unknown to us.

We know only the order of our perceptions.