"Let a man examine his own thoughts," says Pascal, "and he will always find them employed about the time past or to come. We scarce bestow a glance upon the present; or, if we do, 'tis only to borrow light from hence to manage and direct the future. The present is never the mark of our designs. We use both past and present as our means and instruments, but the future only as our object and aim. Thus we never live, but we ever hope to live; and under this continual disposition and preparation to happiness, 'tis certain we can never be actually happy, if our hopes are terminated with the scene of this life." The Thracians, according to Pliny, estimated their lives mathematically, making careful study and count of each day before any event of it was forgotten. "Every day they put into an urn either a black or a white pebble, to denote the good or bad fortune of that day; at last they separated these pebbles, and upon comparing the two numbers together, they formed their judgment of the whole of their lives." But time, past or present,--time, what is it? "Who can readily and briefly explain this?" inquired St. Augustine. "Who can even in thought comprehend it, so as to utter a word about it? But what in discourse do we mention more familiarly and knowingly, than time? And we understand, when we speak of it; we understand, also, when we hear it spoken of by another. What then is time? If no one asks me, I know; if I explain it to one that asketh, I know not; yet I say boldly, that I know that if nothing passed away, time passed were not; and if nothing were coming, a time to come were not; and if nothing were, time present were not. Those two times then, past and to come, how are they, seeing the past now is not, and that to come is not yet? But the present, should it always be present, and never pass into time past, verily it should not be time, but eternity. If, therefore, time present, in order to be time at all, comes into existence only because it passes into time past, how can we say that that is in existence, whose cause of being is that it shall not be? How is it that we cannot truly say that time is, but because it is tending not to be?" Comprehend this, and you see how easy a thing it was for the Thracians to "form a judgment of the whole of their lives"--to strike a nice balance between their happiness and their misery.