As the Writers in Poetry and Fiction borrow their several Materials from outward Objects, and join them together at their own Pleasure, there are others who are obliged to follow Nature more closely, and to take entire Scenes out of her. Such are Historians, natural Philosophers, Travellers, Geographers, and in a Word, all who describe visible Objects of a real Existence.

It is the most agreeable Talent of an Historian, to be able to draw up his Armies and fight his Battels in proper Expressions, to set before our Eyes the Divisions, Cabals, and Jealousies of great Men, and to lead us Step by Step into the several Actions and Events of his History. We love to see the Subject unfolding it self by just Degrees, and breaking upon us insensibly, that so we may be kept in a pleasing Suspense, and have time given us to raise our Expectations, and to side with one of the Parties concerned in the Relation. I confess this shews more the Art than the Veracity of the Historian, but I am only to speak of him as he is qualified to please the Imagination. And in this respect Livy has, perhaps, excelled all who went before him, or have written since his Time. He describes every thing in so lively a Manner, that his whole History is an admirable Picture, and touches on such proper Circumstances in every Story, that his Reader becomes a kind of Spectator, and feels in himself all the Variety of Passions which are correspondent to the several Parts of the Relation.

But among this Sett of Writers there are none who more gratifie and enlarge the Imagination, than the Authors of the new Philosophy, whether we consider their Theories of the Earth or Heavens, the Discoveries they have made by Glasses, or any other of their Contemplations on Nature. We are not a little pleased to find every green Leaf swarm with Millions of Animals, that at their largest Growth are not visible to the naked Eye. There is something very engaging to the Fancy, as well as to our Reason, in the Treatises of Metals, Minerals, Plants, and Meteors. But when we survey the whole Earth at once, and the several Planets that lie within its Neighbourhood, we are filled with a pleasing Astonishment, to see so many Worlds hanging one above another, and sliding round their Axles in such an amazing Pomp and Solemnity. If, after this, we contemplate those wild Fields of Æther, that reach in Height as far as from Saturn to the fixt Stars, and run abroad almost to an Infinitude, our Imagination finds its Capacity filled with so immense a Prospect, and puts it self upon the Stretch to comprehend it. But if we yet rise higher, and consider the fixt Stars as so many vast Oceans of Flame, that are each of them attended with a different Sett of Planets, and still discover new Firmaments and new Lights that are sunk farther in those unfathomable Depths of Æther, so as not to be seen by the strongest of our Telescopes, we are lost in such a Labyrinth of Suns and Worlds, and confounded with the Immensity and Magnificence of Nature.

Nothing is more pleasant to the Fancy, than to enlarge it self by Degrees, in its Contemplation of the various Proportions which1 its several Objects bear to each other, when it compares the Body of Man to the Bulk of the whole Earth, the Earth to the Circle it describes round the Sun, that Circle to the Sphere of the fixt Stars, the sphere of the fixt Stars to the Circuit of the whole Creation, the whole Creation it self to the infinite Space that is every where diffused about it; or when the Imagination works downward, and considers the Bulk of a human Body in respect of an Animal, a hundred times less than a Mite, the particular Limbs of such an Animal, the different Springs which2 actuate the Limbs, the Spirits which set these Springs a going, and the proportionable Minuteness of these several Parts, before they have arrived at their full Growth and Perfection. But if, after all this, we take the least Particle of these Animal Spirits, and consider its Capacity of being Wrought into a World, that shall contain within those narrow Dimensions a Heaven and Earth, Stars and Planets, and every different Species of living Creatures, in the same Analogy and Proportion they bear to each other Verso in our own Universe; such a Speculation, by reason of its Nicety, appears ridiculous to those who have not turned their Thoughts that way, though at the same time it is founded on no less than the Evidence of a Demonstration. Nay, we might yet carry it farther, and discover in the smallest Particle of this little World a new and inexhausted Fund of Matter, capable of being spun out into another Universe.

I have dwelt the longer on this Subject, because I think it may shew us the proper Limits, as well as the Defectiveness of our Imagination; how it is confined to a very small Quantity of Space, and immediately stopt in its Operations, when it endeavours to take in any thing that is very great, or very little. Let a Man try to conceive the different Bulk of an Animal, which is twenty, from another which is a hundred times less than a Mite, or to compare, in his Thoughts, a length of a thousand Diameters of the Earth, with that of a Million, and he will quickly find that he has no different Measures in his Mind, adjusted to such extraordinary Degrees of Grandeur or Minuteness. The Understanding, indeed, opens an infinite Space on every side of us, but the Imagination, after a few faint Efforts, is immediately at a stand, and finds her self swallowed up in the Immensity of the Void that surrounds it: Our Reason can pursue a Particle of Matter through an infinite Variety of Divisions, but the Fancy soon loses sight of it, and feels in it self a kind of Chasm, that wants to be filled with Matter of a more sensible Bulk. We can neither widen, nor contract the Faculty to the Dimensions of either Extreme. The Object is too big for our Capacity, when we would comprehend the Circumference of a World, and dwindles into nothing, when we endeavour after the Idea of an Atome.

It is possible this defect of Imagination may not be in the Soul it self, but as it acts in Conjunction with the Body. Perhaps there may not be room in the Brain for such a variety of Impressions, or the Animal Spirits may be incapable of figuring them in such a manner, as is necessary to excite so very large or very minute Ideas. However it be, we may well suppose that Beings of a higher Nature very much excel us in this respect, as it is probable the Soul of Man will be infinitely more perfect hereafter in this Faculty, as well as in all the rest; insomuch that, perhaps, the Imagination will be able to keep Pace with the Understanding, and to form in it self distinct Ideas of all the different Modes and Quantities of Space.

O.