Physically many cats are able to get pregnant as young as only six or seven months old. However, it is better and healthier for pregnancy to occur when they're a little older. Often younger cats are not good mothers; the maternal instinct seems to be better developed when they're one year or older.
Initially, all modern linguistics was historical in orientation. Even the study of modern dialects involved looking at their origins. Ferdinand de Saussure 's distinction between synchronic and diachronic linguistics is fundamental to the present day organization of the discipline.
Historical knowledge is the knowledge of what mind has done in the past, and at the same time it is the redoing of this, the perpetuation of past acts in the present. (R.G. Collingwood) Nothing capable of being memorized is history.