The Institutes of the Christian Religion, Book 2 · Chapter 8 · Commandment 6
The sixte Commaundement.
Thou shalte not kyll.
The ende of thys commaundemente is, that for asmuche as God hathe bounde together all mankinde with a certaine vnitie, that eueryevery man ought to regarde the safetie of all men, as a thinge geuen hym in charge. In summe therfore, all violence and wronge, yea and all harme doinge, whereby oure neighboures bodie maie bee hurte, is forbidden vsus. And therefore we are commaunded, if there be any power of succore in oure trauaile to defende the life of oure neighboures, that we faithfully imploye the same, that wee procure those thynges that maye make for theyr quiet, that we watche to keepe them from hurte, and yf they be in any daunger, that we geue them our helping hande. If thou consider that it is God the lawmaker that so saithe, then thinke withall that his meaninge is by thys rule also to gouerne thy soule. For yt mere a fonde thinge to thynke, that he which espieth the thoughtes of the hearte, and principally resteth vponupon them, shoulde instructe nothing but the body to true righteousnesse. Therfore the manslaughter of the hearte is also forbidden in this lawe, and an inwarde affection to preserue oure brothers life is here geuen in commaundement. The hande in deede bryngeth fourth ye manslaughter, but the minde conceiueth it, when it is infected with wrathe and hatred. Loke whether thou canst be angry wyth thy brother wythout burning in desire to do him hurt. If thou canst not be angry with him, then canst thou not hate him, for asmuche as hatred is nothynge butte an olde rooted anger. Although thou dissemble and goe aboute to winde oute thy selfe by vaine circumstances: yet where anger or hatred is, there is an effection to hurte.i. Ihō. v. If thou wilte styll dallye oute with shyftes to defende it, it is allready pronounced by the mouthe of the holy Ghooste, that hee is a mansleyer that hatethe hys brother in hys hearte. It is pronounced by the mouthe of the Lorde Christe, that hee is gyltye of iudgemente that is angry wyth hys brother:Mat. v.xxv. that hee ys gyltye of the counsell that saythe Racha: that hee is gyltye of Hell fyer, that saythe vntounto hym, Foole.
The Scripture noteth twoo poyntes of equitie, vponupon whyche this commaundement is grounded: bycause manne is bothe the image of God and oure owne fleshe, wherefore vnlesse we well defyle the image of God, wee muste hauehave care to touche manne none otherwyse, than as a sacred thynge: and vnlesse we will putte of all naturallnesse of man, we muste cheryshe him as oure owne fleshe. That manner of exhortation yt is fetched from ye redemption and grace of Christ, shall be entreated of in an other place. God willed these twoo thinges naturally to be considered in man, that myght perswade vsus to the preseruation of him, that we sholde both reuerence the image of God emprinted in him, and embrace oure owne fleshe. He hathe not therfore escaped the crime of manslaughter, that he hathe kepte him selfe from shedinge of blode. If thou committe any thinge in dede, if thou go about any thinge with endeuoure, if thou conceiue any thynge in desire and purpose that ys against the safetie of an other, thou arte holden gilty of manslaughter. And againe: If thou do not trauayle to thy power and as occasion may serue to defende his life, thou doest with like haynousnesse offende the lawe. But if there be so muche care taken for the safetie of his body, let vsus hereby gather, howe muche studie and trauaile is due to the safetie of hys soule, whyche in the Lorde syght dothe infinitely excell the bodye.