The ethical system that embraces human’s inclination for self-preservation would be the natural law. It is the body of laws that are derived from right reason and nature. It is what is considered ethically right. Hope this answers the question. Have a nice day.
A semi-vegetarian is when they usually eat plant-based foods but sometimes will eat meat.
a lactovegetarian eats plant-based foods and dairy but doesn't eat eggs.
a Lacto-Ovo vegetarian eats only dairy products, plant-based foods, and eggs.
They all have some plant-based foods in their diets. a semi-vegetarian is the only one who will sometimes eat meat. a lactovegetarian and Lacto-Ovo vegetarian are almost the same, the only difference being that one eats eggs while the other doesn't.
I hope this helps, Goodluck!