It is obvious in all this sacrificial ritual that the officiating person or persons were expected to observe the traditional forms with the utmost care and exactness. Any slip or omission was, in fact, a _piaculum_, or _sacrum commissum_--terms of the _ius divinum_ which seem to suggest, if I may use the expression, the obverse side of holiness. It is now well known that cleanness and uncleanness, holiness and its opposite, can be expressed in religious vocabulary by the same terms, for in both cases there is something beyond the ordinary, something dangerous, uncanny; thus we are not surprised to find that such words as I have just mentioned can be used to express some kind of impurity caused by a breach of ritual as well as that ritual itself. If we accept the latest theory of sacrifice, _i.e._ the dynamic theory, as it is called, we explain this intense nervousness about a ritualistic flaw as occasioned by the consciousness of a breach in the current of "religious force" (the expression is that of Messrs. Hubert and Mauss[399]), which must pass in regular sequence from the sacrificer through the victim to the deity, or vice versa. If this is the true explanation--and at present it may be said to hold the field--then the extreme exactness of the Roman ritual was a survival from an age when this strange feeling was a reality; but no more than a survival, for, so far as I can discover, the Roman idea was rather that the deity to whom the ritual was addressed was in some way offended by the omission.[400] The dynamic notion is lost, if it ever were there, and its place has been taken by one that we may perhaps call theological. But however that may be, the culprit was regarded as in a state of sin or impurity, "un etre sacre," and had to get rid of this sin or impurity by another sacrifice before the whole ritual could be started afresh (_instaurare_). According to the "dynamic" theory of sacrifice, we might naturally expect that the victim, as being destined to carry away the unholiness (or whatever we choose to call it) of the culprit, would be burnt whole, not offered to the deity in the form of exta, or eaten by the sacrificers.[401] But this does not seem to have been the case in the Roman practice; in all the examples of _piacula_ of which we have details, the exta are laid on the altar as in the typical sacrifice.[402] The inference seems to be that the theological idea of sacrifice had established itself completely ever since the formation of the _ius divinum_; the victim is not a scapegoat in any sense, but really an expiatory offering; and not only does the sacrificer yield up something of value, but he offers it to increase the strength of the deity as well as to appease his anger.