Ch1 L19: Signs (icon, index, symbol)

  1. I should confess that the challenge, to make a logical continuum, is more complex than I considered. The ideas are so intertwined that I need to leave discussing beliefs and go back to the concept [1] and develop some ideas, knowing that we haven’t finished the discussion about the hierarchy of meanings [2] and the fight between the head and heart [3]. 
  2. We discussed that conceptual meaning is abstract [4]; thus, we need language to think about it [5]. Prior to creating a concept, we also studied signs and supersigns [6], what our brain creates to relate things to each other.
  3. According to semiotics [7], a sign is something which signifies meaning. Ferdinand de Saussure [8] stated that each sign consists of two parts: A signifier and signified [9]. The signifier is the form, structure, or what we perceive; on the other hand, the signified is the meaning, message, or what we conceive. 
  1. In the sign above, the signifier is the picture of a lady, holding her index finger in front of her lips and the signified is obviously (?) silence.
  2. Charles Sanders Pierce [10] classified signs based on the relationship between signifiers and signifieds into three categories:
    1. An icon is a sign such that its signifier has a physical resemblance with its signified.
    2. An index refers to a causal relationship between a signifier and signified.
    3. A symbol is created based on the relationship that people (mainly in a group) make between a signifier and signified.
  3. In the 8th post, we talked about the iconic and indexical relationship that our brain creates between an object and its supersign. I had borrowed “sign” from the terminology of semiotics and that’s also why I decided to name the units of information in the brain, sign [11].  
  1. The above self-portrait of Van Gogh [12] is an icon of Vincent Van Gogh. You can easily detect the physical resemblance. It’s important to know that in order to recognize the connection, you must’ve known Van Gogh, or there wouldn’t be any relationship.
  2. Since indexes stemmed from causality [13], they enable us to infer and predict.
  1. Looking at the tail, we can easily deduce that there must be a cat under the leaves. How can we do that? Because the tail is an index of a cat. You might be wondering there’s no causal relationship in this case. I’d like to define that the existence of the tail is caused by the existence of the cat. So, we wouldn’t need to consider two different definitions for indexical signs.
  2. Another example would be having a fever which is an index of a disease.
  1. The Statue of Liberty [14] is a symbol of freedom. There’s no physical resemblance or causal implication between them. It’s been socially defined so.
  2. We’re gonna discuss signs and relate them to language in the next post. However, the last point to make is that a signifier can be interpreted as an icon, index, or symbol.
  3. The statue below is an icon of Winston Churchill [15]; it can be an index of the second world war because the V-sign was used during WWII [16]; finally, it can be defined as a symbol of victory.


  1. Is a man dressed up as a Santa Claus an icon or a symbol?


[1] Link to the post about concepts.

[2] Link to the post about the hierarchy of meanings. it’s been discussed in the following posts as well.

[3] We started studying the fight between emotion and thinking, but we haven’t covered it all. You can find the discussion in the following links. Link1 Link2

[4] You can refer to the link in the first footnote as well.

[5] We discussed this idea in paragraph 144.

[6] Sign is the smallest unit of information that our brain creates and supersign (the term I’ve come up with) is a system of signs which let us make relationships between them. Link

[7] Link to semiotics

[8] Link to a page about Ferdinand de Saussure.

[9] You can refer to the link to learn more about signifier-signified.

[10] Link to Charles Sanders Pierce.

[11] At first I wanted to call them images because it would be easier to visualize them. But I found out that it’s easier to call them a sign, so we can connect the physical signs to the mental ones since they function similarly.

[12] Link to Vincent Van Gogh.

[13] We’re gonna discuss causality later since it’s one of the pillars of logic and mathematics.

[14] Link to the Statue of liberty.

[15] Link to Winston Churchill.

[16] Link to V sign.


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