This verse points out the two classes for which the book will be useful:
(1) the “simple,” literally the “open,” the open-hearted, the minds ready to receive impressions for good or evil Proverbs 1:22; and
(2) the “young,” who need both knowledge and discipline.
To these the teacher offers the “subtilty,” which may turn to evil Exodus 21:14 and become as the wisdom of the serpent Genesis 3:1, but which also takes its place, as that wisdom does, among the highest moral gifts Matthew 10:16; the “knowledge” of good and evil; and the “discretion,” or discernment, which sets a man on his guard, and keeps him from being duped by false advisers. The Septuagint renderings, πανουργία panourgia for “subtilty,” αἴσθησις aisthēsis for “knowledge,” ἔννοια ennoia for “discretion,” are interesting as showing the endeavor to find exact parallels for the Hebrew in the terminology of Greek ethics.