I suspect many Catholics have been taken aback by the judgement of Cardinal Robert Sarah, prefect of the Congregation for Divine Worship and the Discipline of the Sacraments, in the foreword to a new book that Communion in the hand is the battleground of the most recent engagement between the good angels and Lucifer and his demons. As to the cardinal’s evidence for this skirmish, I shall not comment; as to his liturgical judgement that receiving Communion on the tongue while kneeling, “is much more suited to the sacrament itself”, some observations can be made.
Exactly when receiving on the tongue became common is by no means clear, but it is certainly a result of the move to unleavened “altar bread” which spread in the west in the ninth and tenth centuries.