The main goal of this thesis is to present the idea that the networking logic of the dynamics and structures of network society, mostly in the scope of mass self-communication, is the key to understanding the post-truth condition. In the course of the paper, an attempt is made to develop an argumentation that explains how the development of the notion of post-truth is the result of several primarily social trends that have been set in motion before and during the rise of network society. In hopes of achieving that, the work mainly relies on the theory developed by Manuel Castells that engages the topics of network society and communication power. In scope of the work, a few examples are provided to illustrate the mechanisms, range and effects of disinformation and misinformation. They include: the first examples of corporate-funded science denial, the US presidential elections in 2016, Reddit's response as a social media in the combat against misinformation, and the example of the infodemic as one of the most dangerous types of information disorders. The examples serve to showcase the ways in which the interaction of primarily the political, economic and media domain shape social trends that foster the development of a social environment (post-truth condition) that enables the manifestation of information disorder. It's mostly evident through the effects or consequences those social trends have had on weakening the public sphere and public discourse, the ability of the public to discern facts from disinformation and misinformation, and the proliferation of information disorder. In conslusion, a few observations are made about how dangerous and detrimental information disorder is to society in the frame of post-truth condition, and a suggestion is made on how to combat it.