Date: 1724

"The sudden Gusts of these Passions being thus accounted for, when they become extreme they drive about the Blood with such a Hurricane, that Nature is overset, like a Mill by a Flood: So that what drove it only quicker round before, now intirely stops it, and renders the Countenance pale and gha...

— Cheyne, George (1671-1743)

Date: 1724

"But if the Passions be raging and tumultuous, and constantly fuelled, nothing less that He, who has the Hearts of Men in his Hands, and forms them as a Potter does his Clay, who stills the raging Seas, and calms the Tempests of the Air, can settle and quiet such tumultuous, overbearing Hurricane...

— Cheyne, George (1671-1743)

Date: November, 1740

"The storms and tempests were not alone removed from nature; but those more furious tempests were unknown to human breasts."

— Hume, David (1711-1776)

Date: 1748, 1777

"The internal principles and motives may operate in a uniform manner, notwithstanding these seeming irregularities; in the same manner as the winds, rain, cloud, and other variations of the weather are supposed to be governed by steady principles; though not easily discoverable by human sagacity ...

— Hume, David (1711-1776)

Date: 1751, 1777

"Tempests were not alone removed from nature; but those more furious tempests were unknown to human breasts, which now cause such uproar, and engender such confusion."

— Hume, David (1711-1776)

Date: 1751, 1777

"There seems here a necessity for confessing that the happiness and misery of others are not spectacles entirely indifferent to us; but that the view of the former, whether in its causes or effects, like sun-shine or the prospect of well-cultivated plains, (to carry our pretensions no higher), co...

— Hume, David (1711-1776)

Date: 1767

"These topics will, for the most part, be very extraordinary, and altogether unexpected; but they will constantly produce the intended effect. They will operate upon the mind by surprise; they will strike like lightening, and penetrate the heart at once."

— Duff, William (1732-1815)

Date: 1774

"This activity of imagination, by which it darts with the quickness of lightning, through all possible views of the ideas which are presented, arises from the same perfection of the associating principles, which produces the other qualities of genius."

— Gerard, Alexander (1728-1795)

Date: 1776

"Whatever regards the analysis of the operations of the mind, which is quicker than lightning in all her energies, must in a great measure be abstruse and dark."

— Campbell, George (1719-1796)

Date: 1783

The human body is like a barometer: "If the external air can affect the motions of so heavy a substance as mercury, in the tube of the barometer; we need no wonder, that it should affect those finer fluids, that circulate through the human body."

— Beattie, James (1735-1803)