Merriam-Webster dates the English word to 1663, but the practice is ancient. Augustine set the ground rule in the fifth century: angel names the office, not the nature, spirit is what they are, angel is what they do. Aquinas turned it into a formal branch of theology in the thirteenth century, with the Summa Theologiae's angel questions and a dedicated treatise, De substantiis separatis. The medieval syllabus covered creation date, knowledge, speech, number, and movement of angels with forensic seriousness.
Everyone knows scholastics debated how many angels dance on the head of a pin. No medieval text asks it. The question is a seventeenth-century satire, attributed by later writers to mock the genre, projected backward onto Aquinas. The real debates were stranger: whether angels know singulars, whether they can move continuously or only discretely, whether one angel can occupy the same place as another.
The claim: the discipline's real function was never description but policing, defining angels precisely so that folk experience, visions, and private revelations could be sorted into orthodox or heretical, real angel or demon in disguise. Verdict: substantially true, the manuals doubled as discernment guides for inquisitors, and the Council of Rome in 745 struck angel names from veneration for exactly this reason. A taxonomy of the invisible is also a license to arrest the wrong kind of visionary.
If angels needed a science, what were the unscientific versions doing?