What's real?
This is perhaps the biggest question of all.
Our best strategy for understanding reality is based on objective evidence (facts) and has a name: scientific method. It is humble, acknowledges uncertainties, limitations, possible errors associated to all available evidence, and exploits them to constantly improve our knowledge.
This is really something that should concern everyone, not only scientists, because it is a mindset that revolutionized our view of the world and enormously improved our lives.
Simply because... science works. It is our unique hope for addressing the challenges we face as individuals and community, which already threaten our very existence.
