Immaterial, spiritual, incorporeal are comparable when meaning not composed of matter.
Immaterial is the most comprehensive of these terms because it makes the line of cleavage between itself and its opposite, material, not only clear and sharp but not open to confusion. If, therefore, one wishes a word to carry no other possible implication immaterial is the appropriate term; it may then apply to things believed to have real but not actual (compare REAL ) or phenomenal existence or to things that are purely mental or intellectual constructions.
Spiritual (see also HOLY ) may imply the absence of the material or tangible. The term, however, so often applies to something which has another side or nature variously spoken of as material, animal, physical, or bodily that the word is frequently used, not to describe the character of a whole (a man, all creatures, a belief, or the world), but to distinguish the part which has the nature of a spirit or soul from the part which has not. In distinction from immaterial it frequently, therefore, connotes a supernatural, an intellectual, or a moral character.
Incorporeal basically denies the possession or presence of a body or material form; in general use it usually suggests invisibility, but, especially in legal use, it may imply intangibility or impalpability.