# A Dialogue Concerning the Essence and Role of Information in the World System
## 2 The Dialogue
Is the GTI a logically formalized mathematical theory? **M**: The answer to your question is yes and no, because the GTI has three parts. One is an informal methodological system, another is an operational mathematical theory, and the third is a logically formalized mathematical theory. Thus, the GTI is a methodological system and a logically formalized mathematical theory at the same time. The first part of the GTI is built on principles, which describe and explain the essence and main regularities of the information terrain. It is possible to find the most detailed exposition of this methodological system in the book [11]. The second part utilizes various mathematical structures such as categories, functors, epistemic spaces, named sets, operators, and transformations. It is possible to get acquainted with the operational mathematical theory of the GTI in the publications [12; 13; 14; 18; 19]. The third part uses postulates and axioms to deduce the properties of information and its functioning. Postulates are formalized representations of principles, while axioms describe mathematical and operational structures used in the general theory of information. This part is only initiated and is still waiting for its full development. **J**: Do you mean that to understand the GTI, we have to start from the principles? **M**: You are right. So, let us look at the principles of the GTI. There are two groups of principles. Principles from the first group are called _ontological principles_. They explain the essence of information as a natural and artificial phenomenon as well as depict regularities of information functioning. Here is the list of these principles. **Ontological Principle O1 (the _Locality Principle_)**. It is necessary to separate information in general from information (or a portion of information) for a system \(R\). **Ontological Principle O2 (the _General Transformation Principle_)**. In a broad sense, _information_ for a system \(R\) is a capacity to cause or to prevent changes in the system \(R\). **Ontological Principle O3 (the _Embodiment Principle_)**. For any portion of information \(I\), there is always a _carrier_\(C\) of this portion of information for a system \(R\). **Ontological Principle O4 (the _Representability Principle_)**. For any portion of information \(I\), there is always a _representation_\(C\) of this portion of information for a system \(R\). **Ontological Principle O5 (the _Interaction Principle_)**. A transaction/transition/transmission of information goes on only in some _interaction_ of \(C\) with \(R\). **Ontological Principle O6 (the _Actuality Principle_)**. A system \(R\) accepts a portion of information \(I\) only if the transaction/transition/transmission causes corresponding transformations in \(R\). **Ontological Principle O7 (the _Multiplicity Principle_)**. One and the same carrier \(C\) can contain different portions of information for one and the same system \(R\). As you can see these principles can be divided into three groups:  
* _Substantial ontological principles_ [O1, O2, and its modifications O2g, O2a, O2c] define information. * _Existential ontological principles_ [O3, O4, O7] describe how information exists in the physical world. * _Dynamical ontological principles_ [O5, O6] show how information functions. **J**: Indeed, these principles provide an organized structural view of how information functions. They allow developing a far-reaching theory of information. However, what about a definition of information? **M**: Actually, Ontological Principle O2 gives a definition of information in a generalized sense providing possibilities to define a variety of different types and kinds of information. The most important of them are specified in the following modifications of Ontological Principle O2 [11; 50]. They based on the concept of an infological system. This concept is used as a variable parameter in the definition of information.