Impressions

"Impressions always actuate the soul, and that in the highest degree; but it is not every idea which has the same effect. Nature has proceeded with caution in this case, and seems to have carefully avoided the inconveniences of two extremes. Did impression alone influence the will, we should every moment of our lives be subject to the greatest calamities; because, though we foresaw their approach, we should not be provided by nature with any principle of action, which might impel us to avoid them. On the other hand, did every idea influence our actions, our condition would not be much mended. For such is the unsteadiness and activity of thought, that the images of everything, especially of good s and evils, are always wandering in the mind; and were it moved by every idle conception of this kind, it would never enjoy a moment's peace and tranquility... Nature has therefore chosen a medium, and has neither bestowed on every idea of good and evil the power of actuating the will, nor yet has entirely excluded them from this influence. Thought and idle fiction has no efficacy, yet we find by experience that the ideas of those objects which we believe either are or will be existent produce in a lesser degree the same effect with those impressions, which are immediately present to the senses and perception. The effect, then, or belief is to raise up a simple idea to an equality with our impressions, and bestow on it a like influence on the passions."(DAVID HUME from Treatise of Human Nature)

This has always been very interesting to me. I noticed that thoughts, while having the possibility to be powerful by themselves, are greatly accentuated when accompanied by a physical impression. I remember experiencing certain things as a missionary that I had read about a thousand times that made sense but made no great impression on me, but when the experience took place, it was as if thunder struck. The thought became a brand on my mind and heart when coupled with experience. I know that Hume is saying a lot more here, but this is just what I think of first when reading this.