from those Principles we have here taken, and that Theory we have begun in these two first Books, we can deduce with success and clearness the Origin of the Earth, and those States of it that are already past; Following the same Thred, and by the conduct of the same Theory, we will pursue its Fate and History through future Ages, and mark all the great Changes and Conversions that attend it while Day and Night shall last; that is, so long as it continues an Earth.