I answer that, It is an article of faith that Christ was truly dead: hence it is an error against faith to assert anything whereby the truth of Christ's death is destroyed. Accordingly it is said in the Synodal epistle of Cyril [*Act. Conc. Ephes. P. I, cap. xxvi]: "If any man does not acknowledge that the Word of God suffered in the flesh, and was crucified in the flesh and tasted death in the flesh, let him be anathema." Now it belongs to the truth of the death of man or animal that by death the subject ceases to be man or animal; because the death of the man or animal results from the separation of the soul, which is the formal complement of the man or animal. Consequently, to say that Christ was a man during the three days of His death simply and without qualification, is erroneous. Yet it can be said that He was "a dead man" during those three days.
However, some writers have contended that Christ was a man during those three days, uttering words which are indeed erroneous, yet without intent of error in faith: as Hugh of Saint Victor, who (De Sacram. ii) contended that Christ, during the three days that followed His death, was a man, because he held that the soul is a man: but this is false, as was shown in the FP, Question [75], Article [4]. Likewise the Master of the Sentences (iii, D, 22) held Christ to be a man during the three days of His death for quite another reason. For he believed the union of soul and flesh not to be essential to a man, and that for anything to be a man it suffices if it have a soul and body, whether united or separated: and that this is likewise false is clear both from what has been said in the FP, Question [75], Article [4], and from what has been said above regarding the mode of union (Question [2], Article [5]).