On Abstinence from Animal Food

...they brought. But afterward, as time progressed and kinship kinship (cognatio): the bond of blood and family that expanded from immediate households to entire tribes became more widely spread through mutual procreation, the wild animals were driven out and scattered. Consequently, some individuals began to consider more deeply the benefits gained from living together; they no longer relied merely on a wordless memory of past dangers, as they had before.

From this realization, they attempted to more firmly restrain those who—through a forgetfulness of the past—committed mutual slaughters and thereby weakened human protection original: "humanum præsidium," the collective security and defense found in a united society. To achieve this, they established the legal institutions that are still observed among cities and nations today. The general population willingly assented to these laws because they now perceived a greater sense of utility original: "utilitatis," referring to the practical benefit, safety, and survival of the community in congregating together.

In a similar way, it led to a strict distinction: just as everything harmful was killed without any consideration, so everything that was useful for preventing such death was preserved. For this reason, the killing of humans was rightly forbidden, while the killing of other things was not prohibited at all.

Furthermore, it cannot be argued that there are certain animals that the law permits us to kill despite their not harming human nature or our way of life. For there is none among the animals that the law allows to be killed that would not bring harm to humans if allowed to increase in excessive numbers; conversely, if kept in moderate numbers, each provides certain uses for human life. For the sheep, the ox, and all