[171] and there are many reasons for this. In the first place, the differences which exist in animals are not in one particular only, but are unspeakable in point of number, extending through every part, having reference both to their creation and to the way in which they are furnished with their different faculties, and to their way of being supported and their habits, and to the manner in which they choose and avoid different things, and to the energies and motions of the outward senses, and to the peculiar properties of the endless passions affecting both the soul and body.