I read somewhere that immune responses (and pathogen virulence and reproduction rates) can be erratic enough that you can easy do small experiments that seem to disprove particular routes of contagion of particular diseases. Experiments with proper sample sizes and controls will probably work, but I wonder if some societies would reject the germ theory as disproven by experience or even experiment.<p>It&#x27;s also hard to get proper experimental controls, especially without modern technology and sanitation. And the process of empirically proving the relationship between specific pathogens and diseases is complicated!<p><a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Koch&#x27;s_postulates" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Koch&#x27;s_postulates</a><p>So I guess my concern is that people could have a lot of seemingly compelling experiences that might make them reject the germ theory (or think it was only applicable to a minority of infectious diseases), even after having been told about it in detail.