The controversy chiefly turned on the question of the necessity of episcopacy.
As one of the three principal systems of ecclesiastical polity known to the Christian Church, Presbyterianism occupies an intermediate position between episcopacy and congregationalism.
In episcopacy the supreme authority is a diocesan bishop; in congregationalism it is the members of the congregation assembled in church meeting; in Presbyterianism it is a church council composed of representative presbyters.
The ecclesiastical unit in episcopacy is a diocese, comprising many churches and ruled by a prelate; in congregationalism it is a single church, self-governed and entirely independent of all others; in Presbyterianism it is a presbytery or council composed of ministers and elders representing all the churches within a specified district.
But Presbyterianism was associated in the 2nd century with a kind of episcopacy.