The titles of the lost speeches confirm the statement of Dionysius that the speeches of Isaeus were exclusively forensic; and only three titles indicate speeches made in public causes. The remainder, concerned with private causes, may be classed under six heads:—(1) κληρικοί—cases of claim to an inheritance; (2) ἐπικληρικοί—cases of claim to the hand of an heiress; (3) διαδικασίαι—cases of claim of property; (4) ἀποστασίου—cases of claim to the ownership of a slave; (5) ἐγγύης—action brought against a surety whose principal had made default; (6) ἀντωμοσία (as = παραγραφή)—a special plea; (7) ἔφεσις—appeal from one jurisdiction to another.
Eleven of the twelve extant speeches belong to class (1), the κληρικοί, or claims to an inheritance. This was probably the branch of practice in which Isaeus had done his most important and most characteristic work. And, according to the ancient custom, this class of speeches would therefore stand first in the manuscript collections of his writings. The case of Antiphon is parallel: his speeches in cases of homicide (φονικοί) were those on which his reputation mainly depended, and stood first in the manuscripts. Their exclusive preservation, like that of the speeches made by Isaeus in will-cases, is thus primarily an accident of manuscript tradition, but partly also the result of the writer’s special prestige.
Six of the twelve extant speeches are directly concerned with claims to an estate; five others are connected with legal proceedings arising out of such a claim. They may be classified thus (the name given in each case being that of the person whose estate is in dispute):
I. Trials of Claim to an Inheritance (διαδικασίαι).
1. Or. i., Cleonymus. Date between 360 and 353 B.C.
2. Or. iv., Nicostratus. Date uncertain.
3. Or. vii., Apollodorus. 353 B.C.
4. Or. viii., Ciron. 375 B.C.
5. Or. ix., Astyphilus. 369 B.C. (c. 390, Schömann).
6. Or. x., Aristarchus. 377-371 B.C. (386-384, Schömann).