Sanhedrin

R. Joseph said, The scholars  stated: A heathen is executed for the violation of three precepts — Mnemonic G Sh R—viz., adultery, bloodshed, and blasphemy. R. Shesheth objected: Now bloodshed is rightly included, since it is written, Whoso sheddeth the blood of man, by man shall his blood be shed;  but whence do we know the others? If they are derived from bloodshed,  the other four should also be included; whilst if their inclusion is taught by the extending phrase any man,  should not idolatry too be included?  But R. Shesheth said thus: The scholars stated, A heathen is executed for the violation of four precepts [including idolatry]. But is a heathen executed for idolatry? Surely it has been taught: With respect to idolatry, such acts for which a Jewish court decrees sentence of death [on Jewish delinquents] are forbidden to the heathen. This implies that they are merely forbidden, but their R. Huna, Rab Judah, and all the disciples of Rab maintained: A heathen is executed for the violation of the seven Noachian laws; the Divine Law having revealed this of one [murder], it applies to all. Now is a heathen executed for robbery? Has it not been taught: 'With respect to robbery — if one stole or robbed  or [seized] a beautiful woman,  or [committed] similar offences,  if [these were perpetrated] by one Cuthean33  against another, [the theft, etc.] must not be kept, and likewise [the theft] of an Israelite by a Cuthean, but that of a Cuthean by an Israelite may be retained'?  But if robbery is a capital offence, should not the Tanna have taught: He incurs a penalty? — Because the second clause wishes to state, 'but that of a Cuthean by an Israelite may be retained,' therefore the former clause reads, '[theft of an Israelite by a Cuthean] must not be kept.'  But where a penalty is incurred, it is explicitly stated, for the commencing clause teaches: 'For murder, whether of a Cuthean by a Cuthean, or of an Israelite by a Cuthean, punishment is incurred; but of a Cuthean by an Israelite, there is no death penalty'?  — How else could that clause have been taught? Could he state, 'forbidden' … 'permitted'? Surely it 'A similar act', however, is not taught with reference to murder.  Abaye said: If it should be, however, that it is so taught, it would be in accordance with R. Jonathan b. Saul. For it has been taught; If one was pursuing his neighbour to slay him, and the latter could have saved himself by maiming a limb [of the pursuer, e.g., his foot], and did not thus save himself [but killed him instead],