Hermann, Pernille, Stephen A. Mitchell, and Jens Peter Schjødt, eds., with Amber J. Rose. 2017. Old Norse Mythology—Comparative Perspectives. Milman Parry Collection of Oral Literature 3. Cambridge, MA: Milman Parry Collection of Oral Literature. http://nrs.harvard.edu/urn-3:hul.ebook:CHS_HermannP_etal_eds.Old_Norse_Mythology.2017.
The Æsir and Their Idols
The makers of idols feebly seek to create gods in their own image, but the psalmist hopes that in doing so the makers themselves are deprived of the very facilities with which they are unable to imbue their gods/creations.  Although these idols are anthropomorphic, they do not, unlike humans, possess life, and, unlike God, they have no powers whatsoever. They can do “neither good nor ill” as Jeremiah says (nec male possunt facere nec bene, Jer. 10: 5), and innumerable hagiographic texts use this point to show how utterly foolish it is to put one’s faith and trust in an idol.
The demon who dwells in Astaroth has remarkable powers, but his demonic nature ensures that, strictly speaking, he can do no good: rather, he can do evil and stop doing evil. The demon residing in the idol is capable of making the idol speak or, at least, of speaking from the idol, but he seems unable to animate it further. In the end, according to the saga, the demon is forced to leave, and the empty wooden effigy is subsequently smashed.
This passage is interesting, among other reasons, because Styrmir—if the articuli do indeed stem from his otherwise lost saga about St. Óláfr—idiosyncratically attributes particular cults to each of the Germanic-speaking peoples of northwestern Europe, except the Norwegians, who had embraced the cults of all of these peoples, apparently without having their own particular brand of idolatry or their own supreme god.
Finnr acts aggressively throughout the narrative. He becomes an overzealous follower of King Óláfr, and when the king seeks to convert the Norwegians to Christianity, Finnr, who accompanies him, was often so “óðr ok ákaf at helt við váða þeim er eigi gerðu skjótt hans vilja” (p. 114) (furious and violent that he almost killed those who did not immediately do as he wished). Despite his generally bellicose nature, Finnr’s rage towards the idol is so extraordinary that even King Óláfr Tryggvason himself, who is not otherwise known for his gentleness towards non-Christian practices, is astonished by Finnr’s fury and comments on it. Given that the idol is lifeless, powerless, and empty, it would seem that Finnr goes to extreme lengths in order to destroy it as completely as he does.  However, the metaphysics of cultic figures is complicated. The tale begins by identifying the objects venerated by Sveinn as skurðgoð (idols), but it immediately slips into speaking of them as simply goð (god/gods). The individual idols are referred to as Þórr or Óðinn, the only gods mentioned by name in the text. The text thus illustrates the common slippage from the representation to the represented that is so amply attested throughout the traditional polemic against idols. Sign and signified are united: the god becomes the idol, and the idol becomes the god. In the eyes of the newly converted Finnr, the idol is much more than a powerless piece of wood. It is the god himself, but he is false and utterly impotent.  The standard doctrine held that demons took possession of idols and imbued them with a kind of partial life. But the tale about Sveinn and his son Finnr does not mention demons. Þórr is not a demon. He is pagan god who is as real as the god of the Christians, but he is obviously much weaker. 
This text once again illustrates the doctrine that the idols themselves are powerless and that when they do exhibit some kind of power, it is caused by a devil who moves in once the sacrifices reach an appropriate level.  When confronted with missionaries, the pagans expect their idols to act, but it lies at the very heart of such stories that the idols are destined to be unsuccessful; conversion tales deal after all with successful missionary efforts. Outside the context of mission and conversion, beings created by human hands can occasionally be more effective. One example is found near the conclusion of Ragnars saga loðbrókar. In this saga, a group of sailors lands on Sámsey in Denmark and finds a colossal old idol completely covered in moss as they explore the island. The sailors are discussing the origin of this trémaðr (wooden man) among themselves when they are interrupted by the effigy, which explains in poetic form that it had been erected long ago by the sons of King Ragnarr and that sacrifices were made to it “for the deaths of men in Sámsey in the South”.  The idol in this anecdote is not, and has not been, confronted by a zealous missionary. Therefore it is not predetermined to suffer ridicule and destruction. It is simply presented as an ancient relic of times long past.  The fact that the idol is overgrown with moss, on the other hand, should be taken as a sign that the idol suffers from a lack of veneration.
Although the paragraphs are difficult to translate, it is clear that they prohibit the possession of a stafr (a wooden staff with some kind of representation of a deity?), a stalli (altar?), vitt and blót, which might be designations for items used for sorcery and sacrifices or perhaps objects to which sacrifices are made. The following paragraph shows that the sacrifices/objects to which sacrifices are made (blót) might be made out of dough or clay and given an anthropomorphic shape. The import of the passage is plain: there is a clear interdiction against making effigies of dough or clay and perhaps of wood as well. The purpose of these various kinds of effigies might differ from one item to another, but not so much that the lawmaker could not treat them in the same paragraph.
Among Their gods