Part — Slater, Manual of Moral Theology
Part V. The Fifth Commandment
2.
The crime of homicide is primarily forbidden by this precept, but inasmuch as quarrelling, fighting, wounding, lead up to homicide, these and similar acts are secondarily forbidden. Implicitly, the precept prescribes the preservation of life, since death will follow if care be not taken to preserve life.
p. i, 194