The Latin Church continues to debate a question which is completely settled in the East: when should the Sacrament of Confirmation be conferred? Indeed, practices vary from one diocese to another.
In the light of a recent decision by the Archdiocese of Liverpool to have all children confirmed by their parish priest prior to receiving First Holy Communion, Father Timothy Finigan writes:
The current practice of delaying Confirmation to adolescence has no theological justification: it is a practical measure in order to emphasise conscious commitment or "spiritual adulthood", neither of which have any support in the practice of the Church of the Fathers and both of which could also be seen as a kind of unconscious Jansenism. St Therese found it difficult to get permission to enter the convent at 15. Nowadays in some places she would find it difficult to get confirmed.
Having been confirmed at the age of 9 (or so) myself, I agree with Fr Finigan.
If I may throw in a canonical justification for the presumption of an earlier age for Confirmation, the Code of Canon Law (of the Latin Church) states:
Can. 852 #1. The prescripts of the canons on adult baptism are to be applied to all those who, no longer infants, have attained the use of reason.
One ceases to be an infant at age 7. At age 7, one is presumed to have the use of reason. (Can. 97 #2)
Can. 866. Unless there is a grave reason to the contrary, an adult who is baptised is to be confirmed immediately after baptism and is to participate in the eucharistic celebration also be receiving communion.
So a child aged 7 or above should also be confirmed, unless there is a grave reason to the contrary. Therefore there is the presumption that a child who is 7 or above is capable of receiving and has the right to receive the sacrament of Confirmation.
The requirements for receiving confirmation are
that a person who has the use of reason be suitably instructed, properly disposed, and able to renew the baptism promises. (Can. 889 #2)
This is a very low setting of the bar. "Suitable instruction" will differ according to one's age and condition. "Suitable instruction" is not the same as "in-depth instruction". Note also that the use of reason is not a requirement for the licit reception of this sacrament. But if one has the use of reason, then the other requirements follow.
Can. 890 The faithful are obliged to receive this sacrament at the proper time.
Can. 891 The sacrament of confirmation is to be conferred on the faithful at about the age of discretion unless the conference of bishops has determined another age...
What is the age of discretion? It is to be presumed to coincide with the onset of the use of reason, although there might be need for discretion in those charged with determining whether a person has acquired the discretion necessary for the sacrament. One must be careful not to place so much emphasis on the intellectual capacity of the candidates that the power of grace is insufficiently appreciated. I disagree with the New Commentary on the Code of Canon Law when it says that Can. 889 §2
is a justification for the practice in the Latin church of deferring confirmation until the candidate has reached the age of discretion: the kind of preparation necessary for the reception of confirmation is beyond the intellectual capacity of infants.
This comment appears to pay little regard to the perfectly lawful tradition of the East and would also put in question the confirmation of those affected by various forms of learning difficulties.
The Archdiocese of Southwark's policy (note policy, not law) states that candidates should generally (my emphasis) be a minimum of 12 years. It goes on to say:
The readiness of the person for the sacrament is ultimately more important than their age and any preparation needs to be adapted to the age, ability and maturity of the candidates.
Note: it does not indicate a minum level of ability or maturity.
I think this is a very balanced statement of policy, fully respecting the universal law of the Church and allowing parents and pastors the freedom to exercise their judgement in a discretionary manner.
Go here for a reply from the Congregation for Divine Worship concerning possible conflicts between universal and particular law in this matter. You will see that the CDW sided with the parents and directed that the bishop take steps to ensure that a girl receive Confirmation in spite of the fact that she was below the age set by diocesan policy/law.