1 Corinthians 2:14

But the natural man. — To understand this and other passages in which St. Paul speaks of “natural” and “spiritual” men, it is important to recollect that our ordinary manner of speaking of man as consisting of “soul and body” — unless “soul” be taken in an un-technical sense to denote the whole immaterial portion — is altogether inaccurate. True psychology regards man as a trinity of natures. (See Note on Matthew 10:28.) In accordance with this, St. Paul speaks of man as consisting of body (soma), soul (psyche), and spirit (pneuma); the soma is our physical nature; the psyche is our intellectual nature, embracing also our desires and human affections; the pneuma is our spiritual nature. Thus in each of us there is a somatical man, a psychical man, and a pneumatical man; and according as any one of those parts of the nature dominates over the other, so is the character of the individual person. One in whom the soma is strongest is a “carnal,” or “fleshly,” man; one in whom the intellect or affections pre-dominate is a “natural,” or “psychic,” man; and one in whom the spirit rules (which it can do only when enlightened and guided by the Spirit of God, which acts on it) is a “spiritual” man. (See 1 Thessalonians 5:23.)

Natural. — That is, literally, that part of our nature which we call “mind,” and hence signifies that man in whom pure intellectual reason and the merely natural affections predominate. Now such a one cannot grasp spiritual truth any more than the physical nature, which is made to discern physical things, can grasp intellectual things. Spiritual truth appeals to the spirit of the man, and therefore is intelligible only to those who are “spiritual,” i.e., in whom the pneuma is not dormant, but quickened by the Holy Pneuma.