Bordering pioneer and present in Quote's validation

As human sciences has the face of gradually evolution, it has different and various periods. Analytical and historical approach toward science periods, leads to different periods. In some cases in different scientific era, division is based on date. By reviewing lots of them such as philosophy, verbal, tenet and hadith. The terms like The Eternal and The later generations in evaluating hadith in different periods are remarkably important. Debates on origin, history and circumstances of this division help us so much to understand better. Mostly to Sheikh Toosi is called past The Eternal,before that, Imams period ia called ancient.From Sheikh Toosi to Seyed Ibn Tavous and Allameh Helli is called Fetrat and after that is called The later generations. From past to The later generations is so important. In fact these two periods and its criterion and acale play an important role in cceptance or rejecting the Shiahs Hadith.