(θεωρία), a word used by men of science to denote the real or hypothetical approaches which are made to the discovery of some law of nature real or supposed. When the hypothesis is without verification it does not deserve the name of theory, and when a number of well-established theories have been arrived at, the particular branch of knowledge is then in the fair way of becoming a science. There is, besides, a popular use of the word theory as contrasted with practice, in which the frequent misapplications of the word theory to merely hypothetical knowledge is ridiculed and contrasted sharply with the slow but secure knowledge which experience brings. Any subject which is supposed to be tainted with suppository knowledge, is, on this view of it, held up to scorn, as the dupe of "mere theory."

THEOPHILUS. See MYSTICISM.

THERAPEUTÆ (Θεραπευται, scorshippers), a species of Egyptian ascetics mentioned by Philo Judaeus. Some writers (and among others Scaliger, Mosheim, &c.), identify this sect with the Essenes, while Eusebius regards them as Christians who dwelt in the neighbourhood of Alexandria, and who were converted by Mark. But these views are by no means satisfactory. (See Dr Burton's Lectures on the Eccl. Hist. of the First Century, 2 vols., 1831.)