Is Reason Still Our Guide in a ‘Post-Truth’ Age? Yes, and Everyone Knows It!
We live in a skeptical age that has been dubbed “post-truth.” Yet in their hearts, people know that both truth and reason are important. And this is easy to point out.
Truth in Belief
I began class today asking my high school students why people believe as they do. We listed every reason they could think of on the white board including friends, media, desires, Scripture, parents, hope, fear, and so on. 
Then I showed the students how their answers fit into four categories, as you can see in the chart below:
Then I simply asked then, “Which of these are good reasons for believing something?” We probed each of their responses carefully. They realized that parents are certainly well-meaning but can be mistaken. The students noted that friends and even entire cultures can be wrong. Psychological reasons can be compelling, they noted, but if they are false, they can be harmful in the long run. And they concluded that religious authorities are only worth believing if their teachings are true.
In other words, they concluded that truth is the best reason for believing something.
When I do this activity with students, the conversation often looks like this:
|Me||“I see that many of you listed sociological factors. For example, many of you mentioned that our beliefs are shaped by our parents. Is that a good enough reason to believe something?”|
|Students||“No, not necessarily. Parents can sometimes be wrong!”|
|Me||“Okay, what about cultural factors such as tradition? Do you think people ought to believe something because it has been passed down through tradition?”|
|Students||“No, not necessarily. Traditions are not necessarily wrong, but they are also not necessarily right. Radical Muslims have a tradition of Jihad, but that can’t be right.”|
|Me||“Good. Now some of you mentioned psychological influences such as comfort. Is comfort alone a solid reason to believe something?”|
|Students||“No, we’re not ‘comfortable’ with that. Just because something is comfortable does not make it true. Lies can often be very comfortable!”|
|Me||“So, you’re saying that truth is an important reason to believe something because there can be consequences when people are mistaken?”|
|Students||“Yes, that does seem to be the case.”|
|Me||“What about religious reasons? Should we believe something because Scripture tells us it is true? Should we simply follow whatever a pastor tells us?”|
|Students||“No, because how would we know which Scripture is true? Which religious teachings do we follow? All religious leaders can’t be right.”|
|Me||“Good point. So, how do we know which religion we should follow, if any?”|
|Students||“We would need some outside evidence to indicate that the claims are actually true. There needs to be some proof.”|
|Me||“So, we seem to agree that something is worth believing if we have reason to believe that it is true.”|
As image-bearers of God, people intuitively know that truth is important. We know we should believe things that are supported by evidence and reject things that are false. This exercise simply surfaces what people naturally know.
Once young people see the importance of reason and truth, we can start to explore the next question: “How do we know what is true?” And if we carefully lead in the right way, we can get them to start considering the evidence.
Sean McDowell, Ph.D., is a professor of Christian Apologetics at Biola University, the National Spokesman for Summit Ministries, a best-selling author, popular speaker, and part-time high school teacher. Follow him on Twitter: @sean_mcdowell and his blog: seanmcdowell.org.
Originally appeared at SeanMcDowell.org. Republished with permission.
 I give full credit to my former professor at Talbot School of Theology, the late James Sire, for helping me think through this lesson. He developed this idea in his book Why Good Arguments Often Fail (Downers Grove, IL: InterVarsity Press, 2006), 150-152.