GEN546 To state our theory of desert in its sheer simplicity: The good or worth or value of any thing is its being, where being is construed dynamically and conatively.  Beings make claims, and these constitute their essence, their identity or nature, their prima facie interests and entitlements.  It is because desert is the very reality of things that it is universal and positive in all beings – although, of course, beings may overstep, and the equilibration of deserts in a multifarious universe will never simply serve the unqualified or unreflective claims of a single crude conatus. Universal deserts are bespoken in the biblical protection of the trees of a besieged city Deuteronomy 20:19-20, the land that needs it sabbaths Leviticus 25:8, 26:34, 43; 2 Chronicles 36:21, with Jeremiah 25:11, the ass in the story of Balaam Numbers 22:28, the human person, and even the human form which must not be desecrated or exposed, even after the execution of a criminal Deuteronomy 21:23, nor mutilated, even in the service of God Leviticus 21:5.  The values sketched here are systematized in the Mishnah’s broad rule against wanton destructiveness (bal Tahhit) and in the phased measures taken against a rodef or aggressor in hot pursuit; and, accordingly, in the phased measures taken against a fetus in those rare cases where it becomes a rodef but still merits recognition as a being on the threshold of human life. Biblical humanism is not the rival but the culmination of this general recognition of deserts.  Thus cattle must be milked on the Sabbath, to prevent the suffering of living beings.  A fortiori does Sabbath rest give way in the face of threats to human life or health. The principle of pikuah nefesh [saving a life] rests on the reasoning that the Sabbath is created for us, not we for the Sabbath – and so with all the commandments: “You shall live by them” – not die for them B. Yoma 82a-85b.  Life is the aim, but a certain kind of life, not any sort at all costs.  Life is good, being is good, worthy of sustenance, capable and deserving of nurture.  The humanism articulated in the Mosaic norms, mounted in the larger fabric of love of life and being, provides the grand thematic of the Gemara.  Marking that humanism, Ben Azzai locates the great principle of the Torah in the words of [this verse]. JHRHV 43-4