Theramens continued: “And further, when Antiphon, who during the war supplied from his own means two fast-sailing triremes, was put to death by us (alla mên kai Antiphôntos huph’ hêmôn apollumenou, hos en tô̢ polemô̢ duo triêreis eu pleousas pareicheto), I knew (êpistamên) that all those who had been zealous in the state’s cause (hoti kai hoi prothumoi tê̢ polei gegenêmenoi pantes) would look upon us with suspicion (hupoptôs hêmin hexoien). I objected, also, when (anteipon de kai hote) they said that each of us must seize one of the resident aliens (hote tôn metoikôn hena hekaston labein ephasan chrênai); for it was entirely clear (eudêlon gar ên) that if these men were put to death (hoti toutôn apolomenôn), the whole body of such aliens would become enemies of the government (kai hoi metoikoi hapantes polemioi tê̢ politeia̢ esointo).” (II.iii.40)
The argument Theramenes uses against Critias and the rest of the Thirty concerning their action against the resident aliens in his defence speech is very different from the one he used when the Thirty approached him concerning it.
On the former occasion he is quoted as saying: “But it is not honourable, as it seems to me (All’ ou dokei moi kalon einai), for people who style themselves the best citizens (phaskontas beltistous einai) to commit acts of greater injustice than the informers used to do (adikôtera tôn sukophantôn poiein). For they (ekeinoi men gar) allowed those from whom they got money, to live (par’ hôn chrêmata lambanoien zên eiôn); but shall we, in order to get money, put to death men who are guilty of no wrong-doing (hêmeis apoktenoumen mêden adikountas, hina chrêmata lambanômen;)? Are not such acts altogether more unjust than theirs were (pôs ou tauta tô̢ panti ekeinôn adikôtera;)?” (II.iii. 22)
In his defence speech he argued on the grounds of the impact such action would have on ‘the whole body of resident aliens’. Presumably, the resident aliens played an important part in the economy of Athens, and the action the Thirty had undertaken against the thirty richest resident aliens already proved to have detrimental impact on the other aliens, less rich, but industrious. That’s why he could say in his defence: ‘it was entirely clear (eudêlon gar ên) that if these men were put to death, the whole body of such aliens would become enemies of the government.’
This appears to suggest that the execution of the thirty richest resident aliens and confiscation of their property was seen by the majority of Athenian citizens with satisfaction and approval. It is in this light, I believe, that the law concerning the resident aliens in Plato’s Laws ought to be understood: ‘If an alien acquires property in excess (ean tô̢ xenôn ousia pleiôn gignêtai) of the limit allowed the third property-class (tou tritou megethei timêmatos), then within thirty days of this event he must pack up and be off (hê̢ an hêmera̢ touto gignêtai, triakonta hêmerôn apo tautês tês hêmeras labôn apitô ta heautou), without any right to ask the authorities to extend his stay (kai mêdemia tês monês paraitêsis eti toutô̢ par’ archontôn gignesthô). And if someone disobeys (ean de tis apeithôn) these regulations (toutois) and is taken to court (eisachtheis eis dikastêrion) and convicted (ophlê̢), he must be punished by death (thanatô̢ te zêmiousthô) and his property confiscated by the state (kai ta chrêmata autou genesthô dêmosia).’ (915b5-c4, tr. Trevor J. Saunders)