Concepts and Propositions is a course that examines the importance of concepts and propositions in logic and how they are connected to thought and language. In this blog post I will be covering how concepts are connected to thought and propositions to language, by answering some of the most important questions that are answered in the course. Let’s start with a seemingly simple question:

What is a concept?

Using a technical definition by Ayn Rand, I quote: “A concept is a mental integration of two or more units possessing the same distinguishing characteristics, with their particular measurements omitted.” This definition is very technical so we can make it much simpler using an example. Let’s take the example of the concept “dog”. We can start by giving the concept very basic characteristics that are shared by dogs. 1. Dogs have four legs. 2. Dogs have a tail. Right now this could also be a definition of a cat, that’s why we add more shared characteristics. 3. Dogs bark. The second part of the definition tells us not to use specific measurements as a basis for our concept. For example, if I own two brown dogs, I could make the false assumption that all dogs are brown. We can also change our previously made concept when we learn more. For example, there are dogs with only three legs and no tail, so those can’t be used in the concept for a dog either. We can replace these false characteristics with correct ones such as Dogs are domesticated animals and Dogs are mammals.

What is the difference between a low-order concept and a high-order concept?

Before we can start answering the question we need to know a few things. Let’s start with a simple definition of a hierarchy. “A hierarchy is an ordered series of elements in which later ones depend on earlier ones, all resting on a base that is the resting point.” The hierarch that we are interested in is the conceptual hierarchy, wherein the differentiating factor between parts in the hierarchy is abstractness. Abstractness in this case is the distance from the perceptual level.

What are Propositions?

The technical definition of propositions is: “A proposition is a grammatically structured combination of concepts to identify a subject by a process of measurement-inclusion.” Let’s break the definition down again. The first part of the definition is pretty obvious because a position really just concepts stringed together using words. The second part of the proposition tells us the purpose of the proposition, which is to identify the subject concept and apply the predicate concept to it. The third part of the definition tells us how a proposition does this, which is by using a process of measurement-inclusion. Measurement-inclusion means that you include something in a range because of its measurements. For example, if the range P includes A and B and the measurements of S fall in that range, we can also include S in the P range.

If you want to check out the entire course for yourself, you can check it out here: