and who
must therefore submit to obey their _geasa_. Some of their prerogatives
seem also to be connected with this state of things. Thus they might eat
of certain foods or go to certain places on particular days.[885] In
primitive societies kings and priests often prohibit ordinary mortals
from eating things which they desire for themselves by making them
_tabu_, and in other cases the fruits of the earth can only be eaten
after king or priest has partaken of them ceremonially. This may have
been the case in Ireland. The privilege relating to places may have
meant that these were sacred and only to be entered by the king at
certain times and in his sacred capacity.

As a reflection from this state of things, the heroes of the sagas,
Cuchulainn and Fionn, had numerous _geasa_ applicable to themselves,
some of them religious, some magical, others based on primitive ideas of
honour, others perhaps the invention of the narrators.[886]

_Geasa_, whether in the sense of tabus or of obligations, could be
imposed by any one, and must be obeyed, for disobedience produced
disastrous effects. Probably the obligation was framed as an incantation
or spell, and the power of the spell being fully believed in, obedience
would follow as a matter of course.[887] Examples of such _geasa_ are
numerous in Irish literature. Cuchulainn's father-in-law put _geasa_ on
him that he should know no rest until he found out the cause of the
exile of the sons of Doel. And Grainne put _geasa_ on Diarmaid that he
should elope with her, and this he did, though the act was repugnant to
him.

Among savages the punishment which is supposed to follow tabu-breaking
is often produced through auto-suggestion when a tabu has been
unconsciously infringed and this has afterwards been discovered. Fear
produces the result which is feared. The result is believed, however, to
be the working of divine vengeance. In the case of Irish _geasa_,
destruction and death usually followed their infringement, as in the
case of Diarmaid and Cuchulainn. But the best instance is found in the
tale of _The Destruction of Da Derga's Hostel_, in which the _sid_-folk
avenge themselves for Eochaid's action by causing the destruction of his
descendant Conaire, who is forced to break his _geasa_. These are first
minutely detailed; then it is shown how, almost in spite of himself,
Conaire was led on to break them, and how, in the sequel, his tragic
death occurred.[888] Viewed in this li