Post-truth is a multifaceted and multi-layered problematic that encompasses not only factors unique to our age, but also elements that have accompanied the biological and cultural history of humanity from the very beginning. Existing literature on post-truth largely focuses on external factors such as political manipulations, media strategies and social dynamics, while the cognitive tendencies that play a central role in the emergent epistemic crisis are usually only partially and limitedly addressed. Yet, the sole reason for the devaluation of truth is not external manipulations, but also the cognitive biases inherent in our mental structuring and the epistemic frailty that emerges under their influence. This finding is important in that it transforms the phenomenon of post-truth from being solely a problem of misinformation into an issue originating from the very structure of the human mind. Thus, the main purpose of this study is to reveal how cognitive biases actively shape the ways in which individuals select, interpret and reject information, and to address the individual and social strategies that can be used to combat the negative consequences of these biases.