[quote=Yesh33AD]Why are Catholic celebrants denied the cup and given only the host?
In Catholic terminology, the word “celebrant” usually refers to the priest (who MUST partake of both the Host and the Cup).
In Protestant traditions the cup and body are shared by all.
This is actually the present ordinary practice (since Vatican II) for Catholics as well, so we are in agreement in this practice.
Prior to Vatican II, however, it was not common to offer the Cup to the Laity. The reason dates back to an old heresy.
The Chuch teaches a doctrine called “concomotance,” which means that Jesus is FULLY present under both Species, Bread and Wine (because you can’t consume “half of Jesus”). So, according to Catholic theology, you could consume only the Host (or only the Cup) and receive the “full Jesus.”
Centuries ago, some folks tried to assert that both Forms were *necessary *for valid reception. To help supress this heresy, the Church began to withold the Cup. The tactic worked, and the heresy was supressed. The Cup was restored to the Laity (by Vatican II) once the Church decided there was no longer a valid pastoral reason to withold it.
There may be pastoral reasons not to offer the Cup even in post-Vatican II days. Notably if the priest has nobody to assist him with distribution, and it would be impractical for him to try to offer both forms by himself (this would be more common at a weekday Mass than a Sunday Mass).
Few Catholics would argue that Communion under both Forms is preferable. However, it is absolutely not necessary, as Jesus cannot be divided.