Here is the beginning of a sentence:
Ei gar ousia te^s en hekasto^i arete^s ho heis hyparchein Logos tou THeou me^ amphibeble^tai, ktl.
The meaning is clear, yet I do not understand why "ousia", "ho", "heis", and "Logos" are in the nominative here, rather then in accusative (as the use of the infinitive "hyparchein" seems to me to require). Is there any rule which could explain this?
Many thanks in advance.