Path and fruition for the 4 stages of holy disciple are frequently mentioned. I understand that the fruition is the removal of the fetters and realization of the knowledge of that respective attainment (stream entry, once returner, non returner, arhatship ). The holy disciple knows that he is a stream entrant upon attainment of stream entry fruition.......he knows he is an arhat upon attainment of arhatship. But what is the attainment of path? How would one describe rightly the attainment of the path? What is the difference in an ordinary person, a faithful disciple who has not attained any path and the holy one who has attained any of the respective path? I would really appreciate actual words of the Buddha for this answer.

It is generally held that there are four stages of enlightenment, namely, Soatapanna, Sakadagami, Anagami and Arahant. These stages are achieved by a practitioner as she/he gradually eradicates the ten fetters. I need the complete reference of these topics (four stages and ten fetters) in the first four Nikayas of the Pali canon. Can anyone help me?

Can a arahant recognize other arahants? Can a arahant recognize stream winners, once-returners and never-returners? Can a arahant recognize the spiritual attainment (and conversely, the defilement) of others? If a arahant is able to recognize other arahants, then we may be able to reliably establish a recognized group of arahants in our time, who can be the lead teachers of the sangha worldwide.

I desperately need quotes from either scripture or from scholars.

Did Buddha go through the stages of sotapanna/sakadagami/anagami before his enlightenment? Or did he go straight from a normal person to an arahant and a Buddha during the night of his enlightenment?