15. Now, what is true of the mathematical may

be also true of the moral relations.

We may have

the faculty of perceiving these relations whether they be occupied by actually existent objects or not; or although we should be in ignorance of the objects. On the imagination that one of the inhabitants of the planet Jupiter had the mysterious knowledge of all my movements, and a mysterious power of guidance and protection over me; that he eyed me with constant benevolence, and ever acted the part of my friend and my guardian-I could immediately pronounce on the gratitude and the kind regard that were due from me back again : And should the imagination become a reality, and be authentically made known to me as such, I have a moral nature, a law within my heart, which already tells me how I should respond to this communication. The instance is extravagant; but it enables us at once to perceive what that is which must be fetched to us from without, and what that is which we have to meet it from within. The objects are either made known by observation; or, if they exist without the limits of observation, they are made known by the credible report or revelation of others. But when thus made known, they may meet with a prior and a ready made Ethics in ourselves. The objects may be placed beyond the limits of human experience; but though the knowledge of their existence must therefore be brought to us from afar, a sense of the correspondent moralities which are due to them may arise spontaneously in our bosoms. After the mind has gotten, in whatever way, its information of their reality—

then within the little cell of its own feelings and its own thoughts, there may be a light which manifests the appropriate ethics for the most distant beings in the universe.

16. We are thus enabled to bestow a certain amount of elucidation on a question which falls most properly to be discussed at the outset of Natural Theology. On this distinction between the ethics of the science and the objects of the science, we can proceed at least a certain way in assigning their respective provinces to the light of nature and the light of revelation. But for this purpose let us shortly recur again to the illustration that may be taken from the science of astronomy.

17. Natural Philosophy has two great departments-one of them celestial, the other terrestrial; and it may be thought a very transcendental movement on the part of an inquirer, a movement altogether per saltum, when he passes from the one to the other. Now this is true; but only should it be remarked in as far as it regards the objects of the science. The objects of the celestial lie in a far more elevated region than the objects of the terrestrial; and it may certainly be called a transcendental movement, when, instead of viewing with the telescope some lofty peak that is sustained however on the world's surface, we view therewith the planet that floats in the firmament and at an inconceivably greater distance away from it. There is a movement per saltum when we pass from the facts and data of the one department, to the facts and data of the other. But there is no such move

ment when we pass from the mathematics of the one department to the mathematics of the other. There is, no doubt, in one respect, a very wide transition; when instead of a triangle, whose baseline is taken by a pair of compasses from the Gunter scale, or even measured by a chain on the surface of the earth, we are called to investigate the relations of a triangle whose base-line is the diameter of the earth, or perhaps the diameter of the earth's orbit. There is doubtless a very wide transition from the objects of the terrestrial to those of the celestial physics; when, instead of three indivisible points on the parchment that lies before us, or three signposts of observation that wave on mountain-tops within sight of each other, we have three planetary bodies that, huge though they be in themselves, shrink into atoms when compared with the mighty spaces that lie between them. The fields of observation are wholly different; but it is by the very same trigonometry that we achieve the computation of the resulting triangles. And we again repeat that, sublime as the ascent may be from the facts or data of the one computation to those of the other, there is no gigantic or impracticable stride in their mathematics-that if able to trace certain curves in the page which lies before us, we are further able to scan the cycles of astronomy-that, widely apart as are the revelations of this wondrous science from the conceptions of our first and ordinary experience, yet grant but the facts, and it is by the dint of a familiar and ordinary mathematics, that the mind can ascend to them. It is thus that though

in person we never stepped beyond the humble glen of our nativity, we may have that within the depository of our thoughts, which guides us to the certainties that be on the outskirts of creation. Within the little home of our bosom, there lie such principles and powers, as without one mile of locomotion are of as great avail, as if we could have traversed the infinities of space with the plumb-line in our hand, or carried the torch of discovery round the universe. It does look a marvel and a mystery, how man is able to climb the steep and lofty ascent from the terrestrial to the celestial in Natural Philosophy. But it helps to resolve the mystery, when we thus advert to the distinction between the facts or objects of the science, and the mathematics of the science. It at least tells us what that is, wherein the transition from the one department to the other lies; and gives us to understand that, could we in any way ascertain by observation, certain of the motions and magnitudes that belong to the upper regions of astronomy, there is an instrument within our reach, by which we may come to the accurate determination of its laws.

18. And as with Natural, so with Moral, Philosophy. The former hath its objects, whose properties are found by observation; and these objects have their mathematical relations, most of which are found without observation, by an abstract and solitary exercise of mind on the data which have been previously ascertained. There is a great difference between the terrestrial and the celestial physics, in regard to the way by which we arrive at the data. On the one field they are near at

hand; and at all events do not lie beyond the confines of the globe which we inhabit. On the other field they have place and occupancy at an exceeding distance away from us. The eye in quest of them must lift itself above all earthly objects; and often beyond the ken of our natural vision, they would have been for ever unknown-had not the telescope, that powerful instrument of revelation, fetched them to the men of our world, from those far and hidden obscurities in which they had lain for ages. But whatever the difference may be between the terrestrial and the celestial physics, in regard to the way by which we arrive at their data-there is no such difference in regard to the way through which, by a mathematical process of reasoning, truths are educed from these data. It matters not whether they be the elements of some terrestrial survey, or the observed elements of some distant planet that have been committed to a formula, and made over to the investigations of the analyst. It was indeed a far loftier flight, when in the capacity of an observer, he passed from the stations and the objects of a landscape below to those of the upper firmament. But there was no transition, at all corresponding to this-when passing from the mathematics of the one contemplation to the mathematics of the other. Even at the time when he labours to determine the form or the periods of some heavenly orbit, his mind is only in contact with the symbols of that formula, or with the lines and spaces of that little diagram, which is before his eyes. It is enough that the triangle which comprehends any portion however small of his