[culi]

> The naturalism fallacy is just that, a fallacy.

I disagree. It's a "good enough" rule of thumb.

There are many poisons in nature. Saponins and tannins are extremely poisonous but because they are so widespread in plants and because humans have been eating such a wide variety of plants for so long we've adapted specific pathways to make them basically harmless in standard amounts (some even have medicinal importance). Give those substances to a carnivorous animal and they will suffer or die. Alcohol too is something we've uniquely adapted to. How "poisonous" something is is often a function of how widespread it is. The most lethal poisons are also some of the rarest in nature.

Given the option of two substances, one which we've had 10k years to adapt to and one which was just created in a lab and has structures not like anything commonly found in nature, there is definitely a lower chance that the "natural" substance will be more harmful to you.