…the essence of law consists in its being a conditional truth about the indefinite future, and never can become matter of actual fact. Or we may say it is such a truth that upon the knowledge of it a perpetual or indefinitely lasting conditional expectation may be founded. We say “indefinitely lasting” because as a general rule our laws are vaguely understood to endure only so long as “the present state of things” continues; but that state of things may endure forever, or if it ceases, may return some day.