His earliest publications were essays which appeared in various periodicals. Six of them, written between 1819 and 1828, contain the leading ideas which he subsequently co-ordinated and developed in his larger works. In one of them, the Plan of the scientific works necessary for the Reorganisation of Society, pub lished in 1822, will be found the first announcement of the two famous laws of the Three States and the Classification of the Sciences. These six essays Comte reprinted long afterwards as an appendix to the fourth volume of the Positive, Comte coined the word sociologie in Polity, in order to prove, as they most 1839. See P/zil. Pos., chap. Xlvii.