One of the reasons we should care about epistemic vices is that they harm all of society. Epistemic vices are vices that hinder knowledge, and since we live in complex and interconnected societies, we rely on shared and easily accessible knowledge in order for any of us to survive. When knowledge is hindered, the chance that complex systems can break down and harm people increases.
This idea is important and helpful when we think about our own potential epistemic vices. Our attitudes, behaviors, and actions that hinder knowledge may not harm us, but may harm someone else or may harm broader segments of society. In his book Vices of the Mind Quassaim Cassam demonstrates this by examining epistemic malevolence. He writes, “the person who is deprived of knowledge by the vice of epistemic malevolence is not the person with the vice.”
If someone is intentionally misleading you by giving you false information or making you question legitimate information for their own gain, then they are not harmed. They likely know that the information they are presenting and sharing is inaccurate, but stand to gain from you having inaccurate information. They may stand to profit, which motivates their epistemic malevolence, while you are harmed.
In some epistemic vices, the individual with the vice is the one who is harmed. Wishful thinkers and gullible individuals are the ones who are harmed by their epistemic vices. However, other epistemic vices, as the malevolence example demonstrates, harm other people. Knowledge is something that is shared and built communally. Few of us develop real knowledge completely on our own, and the power of knowledge is magnified when shared with others. Often, when we get in the way of this process, it is not just ourselves that are harmed, but all of society, increasing the responsibility that we all have to minimize epistemic vices.