If there’s a point to terrain, it’s that a living critter like a human is a complex system and disease effects and responses are complex. The idea that a human

If there’s a point to terrain, it’s that a living critter like a human is a complex system and disease effects and responses are complex. The idea that a human being is a biome, with vast numbers of non-human cells active within and necessary for health, would have been shocking in the 18th century and is still sometimes a bit disquieting for me (because it sort of makes me a “we”). There is a terrain in there. Science is better at finding answers to things that have a small number of variables than a large number. (If, for example, autism in offspring is increased by a subtle effect of multiple classes of chemicals during a particular phase of pregnancy followed by another subtle effect in the child’s first year, we will have a very hard time teasing that out. Not pathogenic, but perhaps you get the point.) As to the rest- we observe bacterial, viral and fungal infection in non-humans. Germ theory works well for them too. Germ theory also predicts how disease gets transmitted and which diseases get transmitted (the one you have is the one you give). Flat-earthism is easy enough to debunk in person (if time- and energy-intensive, you just need to spend enough time flying and sailing), and relatively harmless. Anyone acting on terrain beliefs can infect a large number of people with cholera or typhus, that’s a bit more dangerous.