This weekend is ordination weekend in the Diocese of Cleveland. It is always a great thing to go to and the diocese as a whole is invited so go if you can. (Saturday at 10:00 at the Cathedral.) Duties at the parish will keep me from going but Fr. Pfeiffer will be there.
Part of the ceremony is the laying on of hands. The laying on of hands is a prayer calling down the Holy Spirit upon a person. When you think of it, the gesture is beautiful. Extending back through the Bible a man who was likewise ordained and has the faculties (a duly empowered bishop) calls down the Holy Spirit, chooses a man, and signifies the choice to the community all by the laying on of hands. This has been going on in the Catholic Church since its foundation. Therefore in theory I should be able to trace my ordination back to a bishop who can trace his ordination back to a bishop who can trace his ordination back to a bishop all the way back to an Apostle.
This is not the only place that the laying on of hands takes place however. It is also used to call down the Holy Spirit at confirmation. There is a laying of hands at the anointing of the sick also.