Reagan asserts that every living being has inviolable rights which prevent human beings from using them for their benefit. This view, although very altruistic, is very problematic for the everyday existence of humans. Firstly, it is a biological fact that we need food in order to survive. What are the sources of food? Traditionally they have been other animals like chicken, cows, fish and pigs. However, suppose we were to become a non-carnivorous society. What are the other options available? Plants, fruits and vegetables is an obvious place to start. However, how is eating a cabbage or an apple from an apple tree not using living organisms for the benefit of humans? We as humans clearly can not exist if we do not use other living organism necessary for our physical needs.
Regan can argue at this point that plants, trees, bacteria and mosquitos are not part of the living organism group. His requirement for that club is to care about existing. Since trees do not perceive or have feelings they do not care. Therefore, they are not part of living organism and are not worthy of moral consideration. However, this leads to a more fundamental question: what qualifies an organism to be a living being and considered as a moral subject?