Veganism is the practice of abstinence from the use of animal-sourced products, especially for eating (meat, dairy, eggs, possibly honey) but likely including other animal-derived goods (e.g. leather, possibly wool). An “ethical vegan” may also oppose the use of animals for any purpose, including sport, labour and pharmaceutical or other scientific testing.
There's an argument to be made that humans should subsist on a largely plant-based diet1 and it's something that I'd like to experiment with, especially with a view to longevity (LEV towards immortality).
Things to think about …
Until the 20th century, most humans relied on inexpensive, easy to grow grains, but with the introduction of industrial farming and “meat factories” our diets began to change. (There's a good example of a pre-industrial diet in the Bolivian Tsimané, who have little to no heart disease and the cleanest coronary arteries known to science. Modern day foragers with almost entirely plant-based diets.) ↩︎