ABSTRACT
To gain an idea of his catechizing, we must read his De 111ystel'iis. In it St Ambrose addresses the catechumens who had already received Baptism and the Eucharist, and explains to them the profound signification of the ritual which had been carried out before them or upon them. In order to anticipate objections or doubts which might arise in their minds, he takes pains to demonstrate to them that nothing is indifferent in what they had seen, that everything carried a mysterious meaning and a moral efficacy, and was the instrument of regeneration prefigured in so many writings of Scripture.
