Contra Paedocommunion

"At length they object, that there is not greater reason for admitting infants to baptism than to the Lord's Supper, to which, however, they are never admitted: as if Scripture did not in every way draw a wide distinction between them. In the early Church indeed, the Lord's Supper was frequently given to infants, as appears from Cyprian and Augustine (August. ad Bonif. Lib. 1); but the practice justly became obsolete. For if we attend to the peculiar nature of baptism, it is a kind of entrance, and as it were initiation into the Church, by which we are ranked among the people of God, a sign of our spiritual regeneration, by which we are again born to be children of God; whereas, on the contrary, the Supper is intended for those of riper years, who, having passed the tender period of infancy, are fit to bear solid food. This distinction is very clearly pointed out in Scripture. For there, as far as regards baptism, the Lord makes no selection of age, whereas he does not admit all to partake of the Supper, but confines it to those who are fit to discern the body and blood of the Lord, to examine their own conscience, to show forth the Lord's death, and understand its power. Can we wish anything clearer than what the apostle says, when he thus exhorts, "Let a man examine himself, and so let him eat of that bread, and drink of that cup"? (1 Cor. 11:28.) Examination, therefore, must precede, and this it were vain to expect from infants. Again, "He that eateth and drinketh unworthily, eateth and drinketh damnation to himself, not discerning the Lord's body." If they cannot partake worthily without being able duly to discern the sanctity of the Lord's body, why should we stretch out poison to our young children instead of vivifying food? Then what is our Lord's injunction? "Do this in remembrance of me." And what the inference which the apostle draws from this? "As often as ye eat this bread, and drink this cup, ye do show the Lord's death till he come." How, pray, can we require infants to commemorate any event of which they have no understanding; how require them "to show forth the Lord's death," of the nature and benefit of which they have no idea? Nothing of the kind is prescribed by baptism. Wherefore, there is the greatest difference between the two signs. This also we observe in similar signs under the old dispensation. Circumcision, which, as is well known, corresponds to our baptism, was intended for infants, but the passover, for which the Supper is substituted, did not admit all kinds of guests promiscuously, but was duly eaten only by those who were of an age sufficient to ask the meaning of it (Exod. 12:26). Had these men the least particle of soundness in their brain, would they be thus blind as to a matter so very clear and obvious?"

John Calvin (Institutes IV: xvi: 30).