While not strictly authoritative for the PCA, the reasoning in the following stands I think, as it is referenced back to various paragraphs of the PCUS
Book of Church Order, and these paragraphs still stand unchanged in the current PCA
BCO.
From
A Digest of the Acts and Proceedings of the General Assembly of the Presbyterian Church in the United States, 1861-1965, page 65:
Form of Government 12-4
A church does not have choice whether to have Deacons or Board.
1936, p. 40. [Overture asking the Assembly to grant individual churches the option of employing one Board of Officers as the governing body of the church.]--answered in the negative. See the paper on the "
Doctrine of the Diaconate," by Girardeau, Dabney and Peck (1884). While never adopted or endorsed by the Assembly, this paper presents one aspect of the mind of the Church.
1965, pp. 29, 95. That Overture 14 concerning unicameral operation in the local church, be answered with the following statement as recommended by the Permanent Judicial Commission:
An unicameral system already exists in that the Session has supervision and authority over the Deacons (
Section 12-5 and 15-6,
BCO) and thereby has ultimate authority for the proper discharge of the functions of the Deacons. Nevertheless the Deacons must organize as a board with officers and regular meetings (Section 12-4) for the better discharge of the specific duties with which the board is charged (
Section 12-3). It is only in a church in which Deacons cannot be secured that the duties of the office devolve upon its Ruling Elders (Section 15-6).
That Overture 15 relative to the office of Deacon, be answered with the following statement as recommended by the Permanent Judicial Commission:
The Commission recommends that the first proposition of the overture be answered in the affirmative for the reasons set out in the overture and in the provisions of
Section 12-3,
Book of Church Order, which specifies that the office of Deacon is spiritual in nature.
The Commission recommends that the second proposition of the overture be answered in the negative. The Deacons must organize as aq board and elect officers including a Treasurer (
Section 12-4) for the better discharge of the functions primarily committed to them by
Section 12-3. This must not be construed as merely permissive. The Session has the authority in its discretion to employ or to permit the employment of a business administrator for the assistance of the Deacons, but thereby the Deacons are not relieved of any responsibility imposed by
Section 12-3. The office of Deacon is spiritual in nature (
Section 12-2), a quality which is to be exercised, rather than overlooked or suppressed, in the discharge of their duties. The office of Deacon as set forth in Scripture is one of sympathy and service after the example of Christ (
Section 12-1), given for ordering the life of the church along with the office of the Minister of the Word and Sacraments and the office of the Ruling Elder, and to be continued perpetually in the church (
Section 9-2).