in Mental Philosophy. See METAPHYSICS.

in Physiology, the first formation of the embryo or fetus in the womb.

Immaculate, of the Holy Virgin, a feast established in honour of the holy Virgin, particularly with regard to her having been conceived and born immaculate, or without original sin. It is held in the Roman Catholic Church on the 8th of December. The immaculate conception is the great head of controversy between the Scotists and Thomists, the former maintaining and the latter impugning it. The controversy is at present (1854) under the consideration of the pope, and will in all probability be settled by the issuing of a bull in favour of the doctrine. This feast is also celebrated in the Greek Church on the same day, under the title of the Conception of St Anne (the mother of Mary).