DAvid Hume

All a person’s perceptions can be divided into two distinct categories that I will refer to as IMPRESSIONS and IDEAS. The distinction between them is in the intensity and vibrancy with which they penetrate our thoughts or consciousness and affect our state of mind. We can call the perceptions that come most violently and forcefully impressions. Under this umbrella term, I include all of our feelings, passions, and emotions as they initially manifest in the soul. I use the term “ideas” to refer to the hazy representations of these in thought and reasoning, such as all the perceptions sparked by the current conversation, with the exception of those arising from the senses of sight and touch and the potential for immediate pleasure or unease. I don’t think it will be necessary to use a lot of words to describe this difference. Every individual will be able to distinguish between sensation and thinking. These can be easily differentiated by their common degrees, but it is not impossible; in some situations, they might be extremely close to overlapping. Thus, our ideas may become very close to our sensations, whether we are asleep, ill, insane, or experiencing any other really intense emotional state. On the other hand, there are moments when our impressions are so weak and low that we are unable to tell them apart from our ideas. Despite this close resemblance in a few instances, they are often sufficiently dissimilar that no one would hesitate to group them under separate headings and give each one a unique name to indicate the distinction. I think this freedom will be granted to me because I use the terms “impression” and “concept” here in a manner that is distinct from what is customary. Perhaps I should return the word “idea” to its original meaning rather than the distorted one Mr. Locke gave it by having it stand for all of our senses. Since there is no specific name for impressions in either English or any other language that I am aware of, it would be recognized that I am not referring to the process by which our lively perceptions are generated in the soul. Rather, I am referring to the perceptions themselves. It will be useful to note that there is another split inside our perceptions that includes both our impressions and concepts. There are two categories here: SIMPLE and COMPLEX. Simple sensations, impressions, and concepts are those that permit neither differentiation nor distinction. The complicated, which can be divided into sections, is the opposite of these. Even if this apple has a certain color, taste, and fragrance that are all together, it is simple to see that they are not the same thing, if not at least distinct from one another.