Physical and moral inability (Placaeus); the demons cannot love God
Another distinction belongs here, used by Placaeus and many others with him: physical power or inability against moral. Physical inability to act well exists when the natural power of understanding and willing, without which nobody can act either well or badly, is absent or not in its own control.
Moral inability exists when mind and will are present and in their own control, but have been fixed by certain habits on acting badly. Placaeus also puts it another way. Physical inability lies outside the will: it is what keeps you from doing a thing however much you want and try. Moral inability lies in the will itself: you cannot do something because you do not want to, your will being fixed on the opposite by a firm and deep-rooted habit.
This is the inability we see in the demons with respect to loving God. They cannot love God, not for want of any natural faculty needed to love him, but because of their own free will they are entirely hardened in hatred of God.
Latin
XXXIV. Eodem refertur alia distinctio qua utitur idem Placeus, & cum eo alii plurimi. Hic enim distinguunt inter potentiam sive impotentiam Physicam, & Moralem. Impotentia Physica ad bene agendum est, cum potentia naturalis intelligendi & volendi, sine qua nemo vel bene vel male agere potest, aut deest aut sui compos non est: Impotentia vero moralis est, quum mens quidem & voluntas adest, & est etiam sui compos, sed per habitus quosdam ad male agendum determinata est. Vel ut aliis verbis rem eandem explicat Placeus impotentia Physica est quae posita est extra voluntatem, hoc est per quam rem non potes, quantumlibet velis & coneris. Impotentia vero moralis est quae sita est in ipsa voluntate, hoc est, per quam non potes aliquid quia non vis, & habitu firmo ac penitus inhaerente ad oppositum voluntas tua determinata est. Qualis impotentia cernitur in daemonibus respectu amoris in Deum. Etenim Deum amare non possunt, non quod iis desit ulla facultas naturalis necessaria ad Deum amandum, sed quia propria & libera voluntate in Dei odio prorsus obfirmati sunt.