Cannibalism

The Sages taught in a baraita: Eating in the first hourof the morning is the time of eating for Ludim, (who are members of a nation of cannibals, and they are ravenous and hurry to eat. -Rashi)...

(4) 4) I might think that one would be in transgression of the negative commandment against eating the flesh of bipeds (men) and the milk of bipeds (women); and it would follow a fortiori, viz.: Now if (in the instance of) an (unclean) beast, where you have been lenient vis-à-vis its touch (i.e., it is permitted to touch an unclean beast), you have been stringent vis-à-vis its flesh (it is forbidden to eat it), then bipeds, where you have been stringent vis-à-vis touching them (i.e., niddah), how much more so should you be stringent vis-à-vis (drinking) their milk! It is, therefore, written, (in negation): "This" — "This … (is unclean"), but the milk of bipeds is not unclean. — But then I would exclude (from the negative commandment) (only) milk, which does not obtain with all (bipeds), but I would not exclude flesh, which does obtain with all bipeds! It is, therefore, written (two terms of exclusion): "This … unclean is it" — This (the flesh of an unclean beast) is subject to the negative commandment (against eating), but the flesh of bipeds and the milk of bipeds is not subject to the negative commandment against eating.

Human beings, even though the Torah says (Bereishit 2:7) “and then the human became a living animal”, is not in the category of animals with hooves, and therefore is not included in the prohibitive commandment. And someone who eats human flesh or fat, whether from the living or the dead, does not receive the punishment of lashes. However, it is forbidden by force of a prescriptive commandment, for the Written Torah listed the seven permitted animals, and said about them (Vayiqra 11:2) “these are the animals that you may eat” – therefore, whatever is outside those, you may not eat, and a prohibition that is implied by a prescriptive commandment counts as prescriptive. (Thank you Rabbi Stephen Belsky)

Ramban on Vayiqra 11 [And maybe Rambam] thought that based on what we learn there in Torat Kohanim (Sifra, the halakhic midrash on Vayiqra) 4:4 – ‘Does this even include the flesh and milk of those who walk on two legs, that eating them would be forbidden by a prohibition? Therefore the Torah states “do not eat this”; the [flesh of those animals mentioned in the Torah] is forbidden by a proscriptive commandment, but not the flesh or milk of those who walk on two legs. [Rambam] concluded from this, that the prohibition on [human flesh and milk] is not a proscriptive commandment, but instead is based in a prescriptive commandment, derived from the verse "[and these acceptable animals] are the ones you should eat". But it is not so, for our Sages states explicitly (Kritot 21b) that there is not even a rabbinic prohibition on the blood and milk of those who walk on two legs; and if the meat were forbidden, [we would apply the rule that] anything that comes out of the [forbidden] impure is [forbidden] impure as well. But the Sages excluded the blood of humans and of bugs from the prohibition of consuming blood, and said (Makhshirin 6:5) "the blood of a bug is like its flesh", [such that someone who eats it] would receive lashes due to the prohibition of consuming bugs, not blood, since they defined the blood as the flesh itself. But when they said that eating them is not a violation of a proscriptive commandment, it means that there is no rule preventing it, and it is permitted. But according to my opinion, this would only apply to meat from the living – but meat from the dead is [already forbidden] as [our Sages] learned from a gezeira-shava connection to the laws of the ‘Egla ‘Arufa (beheaded calf), which is forbidden to derive benefit from.

If the flesh of a man were forbidden, his blood would have also been forbidden because of the commandment about the flesh of man, and he would have been lashed if he was warned about it because of [the prohibition of eating] man. But here we say that even the [rabbinic] commandment of staying away doesn’t apply to it.

These words apply only to flesh from a living person, but from a dead person – the flesh is forbidden even in deriving benefit, as we learn (Kiddushin 57a) [a g'zeira shava from the verses with the words] “sham” “sham” from ‘Egla ‘Arufa (beheaded calf) – all the more so that it is forbidden for eating.
And the Rambam z”l wrote that the flesh of a man is forbidden by a positive commandment, and he explained that it’s because it is written “these are the animals that you may eat” – and not man. And even though they [the Sages] didn’t learn this anywhere, he leaned on what they wrote in the Sifra “I might think that one would be in transgression of the negative commandment against eating the flesh of bipeds”, and he z”l held that it isn’t in a transgression of a negative commandment, but it is in transgression of a positive commandment.
And this isn’t true, since we find this wording about milk as well, and even in that case we say here that even the commandment of staying away doesn’t apply to it. Here too, even the commandment of staying away is not found in it.