Why is it unwise to think that non-prescribed drugs cannot cause harmful side effects

Every drug, no matter if it's prescribed or not, can cause side effects because every drug consists of some substances. It depends on a particular organism if it's resistant to those substances.

Ifound this on google “aristotle (384–322 bc) in western scientific taxonomy the greek philosopher aristotle was the first to classify all living things, and some of his groups are still used today, like the vertebrates and invertebrates, which he called animals with blood and without blood.” i hope this you for what your looking for.