The great advantages which naturally result from storing the mind with knowledge, are obvious from the following considerations. The association of our ideas is either habitual or instantaneous; and the latter mode seems rather to depend on the original temperature of the mind than on the will. When the ideas, and matters of fact, are once taken in, they lie by for use, till some fortuitous circumstance makes the information dart into the mind with illustrative force, that has been received at very different periods of our lives. Like the lightning's flash are many recollections; one idea assimilating and explaining another, with astonishing rapidity. I do not now allude to that quick perception of truth, which is so intuitive that it baffles research, and makes us at a loss to determine whether it is reminiscence or ratiocination, lost sight of in its celerity, that opens the dark cloud. Over those instantaneous associations we have little power; for when the mind is once enlarged by excursive flights, or profound reflection, the raw materials, will, in some degree, arrange themselves. The understanding, it is true, may keep us from going out of drawing when we group our thoughts, or transcribe from the imagination the warm sketches of fancy; but the animal spirits, the individual character give the colouring. Over this subtile electric fluid,* how little power do we possess, and over it how little power can reason obtain! These fine intractable spirits appear to be the essence of genius, and beaming in its eagle eye, produce in the most eminent degree the happy energy of associating thoughts that surprise, delight, and instruct. These are the glowing minds that concentrate pictures for their fellow-creatures; forcing them to view with interest the objects reflected from the impassioned imagination, which they passed over in nature. (*Footnote. I have sometimes, when inclined to laugh at materialists, asked whether, as the most powerful effects in nature are apparently produced by fluids, the magnetic, etc. the passions might not be fine volatile fluids that embraced humanity, keeping the more refractory elementary parts together--or whether they were simply a liquid fire that pervaded the more sluggish materials giving them life and heat?) I must be allowed to explain myself. The generality of people cannot see or feel poetically, they want fancy, and therefore fly from solitude in search of sensible objects; but when an author lends them his eyes, they can see as he saw, and be amused by images they could not select, though lying before them.