He who is only a traveler learns things at second-hand and by the halves, and is poor authority. We are most interested when science reports what those men already know practically or instinctively, for that alone is a true humanity, or account of human experience.
The beginning, middle, and end of the birth, growth, and perfection of whatever we behold is from contraries, by contraries, and to contraries; and whatever contrariety is, there is action and reaction, there is motion, diversity, multitude, and order, there are degrees, succession and vicissitude.