ST II-II.83.15. Whether prayer is meritorious?
Objection 2. Further, if prayer merits anything, this would seem to be chiefly that which is besought in prayer. Yet it does not always merit this, because even the saints' prayers are frequently not heard; thus Paul was not heard when he besought the sting of the flesh to be removed from him. Therefore prayer is not a meritorious act.
Reply to Objection 2. Sometimes the merit of prayer regards chiefly something distinct from the object of one's petition. For the chief object of merit is beatitude, whereas the direct object of the petition of prayer extends sometimes to certain other things, as stated above (A. 6, 7). Accordingly if this other thing that we ask for ourselves be not useful for our beatitude, we do not merit it; and sometimes by asking for and desiring such things we lose merit for instance if we ask of God the accomplishment of some sin, which would be an impious prayer. And sometimes it is not necessary for salvation, nor yet manifestly contrary thereto; and then although he who prays may merit eternal life by praying, yet he does not merit to obtain what he asks for. Hence Augustine says (Liber. Sentent. Prosperi sent. ccxii): "He who faithfully prays God for the necessaries of this life, is both mercifully heard, and mercifully not heard. For the physician knows better than the sick man what is good for the disease." For this reason, too, Paul was not heard when he prayed for the removal of the sting in his flesh, because this was not expedient. If, however, we pray for something that is useful for our beatitude, through being conducive to salvation, we merit it not only by praying, but also by doing other good deeds: therefore without any doubt we receive what we ask for, yet when we ought to receive it: "since certain things are not denied us, but are deferred that they may be granted at a suitable time," according to Augustine (Tract. cii in Joan.): and again this may be hindered if we persevere not in asking for it. Wherefore Basil says (De Constit. Monast. i): "The reason why sometimes thou hast asked and not received, is because thou hast asked amiss, either inconsistently, or lightly, or because thou hast asked for what was not good for thee, or because thou hast ceased asking." Since, however, a man cannot condignly merit eternal life for another, as stated above (I-II.114.6), it follows that sometimes one cannot condignly merit for another things that pertain to eternal life. For this reason we are not always heard when we pray for others, as stated above (7, ad 2, 3). Hence it is that four conditions are laid down; namely, to ask: "(a) for ourselves, (b) things necessary for salvation, (c) piously, (d) perseveringly"; when all these four concur, we always obtain what we ask for.
Ad quintumdecimum sic proceditur. Videtur quod oratio non sit meritoria.
Ad secundum dicendum quod ad aliud principaliter respicit meritum orationis quandoque quam ad id quod petitur, meritum enim praecipue ordinatur ad beatitudinem; sed petitio orationis directe se extendit quandoque ad aliqua alia, ut ex dictis patet. Si ergo illud aliud quod petit aliquis pro seipso, non sit ei ad beatitudinem utile, non meretur illud, sed quandoque hoc petendo et desiderando meritum amittit, puta si petat a Deo complementum alicuius peccati, quod est non pie orare. Quandoque vero non est necessarium ad salutem, nec manifeste saluti contrarium. Et tunc, licet orans possit orando mereri vitam aeternam, non tamen meretur illud obtinere quod petit. Unde Augustinus dicit, in libro sententiarum prosperi, fideliter supplicans Deo pro necessitatibus huius vitae, et misericorditer auditur, et misericorditer non auditur. Quid enim infirmo sit utile magis novit medicus quam aegrotus. Et propter hoc etiam paulus non est exauditus petens amoveri stimulum carnis, quia non expediebat. Si vero id quod petitur sit utile ad beatitudinem hominis, quasi pertinens ad eius salutem, meretur illud non solum orando, sed etiam alia bona opera faciendo. Et ideo indubitanter accipit quod petit, sed quando debet accipere, quaedam enim non negantur, sed ut congruo dentur tempore, differuntur, ut Augustinus dicit, super ioan.. Quod tamen potest impediri, si in petendo non perseveret. Et propter hoc dicit Basilius, ideo quandoque petis et non accipis, quia perperam postulasti, vel infideliter vel leviter, vel non conferentia tibi, vel destitisti. Quia vero homo non potest alii mereri vitam aeternam ex condigno, ut supra dictum est; ideo per consequens nec ea quae ad vitam aeternam pertinent potest aliquando aliquis ex condigno alteri mereri. Et propter hoc non semper ille auditur qui pro alio orat, ut supra habitum est. Et ideo ponuntur quatuor conditiones, quibus concurrentibus, semper aliquis impetrat quod petit, ut scilicet pro se petat, necessaria ad salutem, pie et perseveranter.