Three Thomist accounts of the premotion; Alvarez's 'virtual motion'
Thesis XLVIII. All of them call this efficacious aid by the name of physical predetermination, and say that it is a gratuitous and prior motion of God that moves the created will and applies it to doing good. Yet some say that this premotion of God, by which human wills are moved to do good, is in the manner of a quality that does not remain but passes away with the will's own operation.
Others say that the actual motion by which God moves the will and applies it to act is really the will's operation itself, insofar as it comes from God, who applies the will to act and efficaciously premoves it.
Finally, others hold that this prior motion is neither in the manner of a quality received in the will nor the same as the will's operation, but something with a kind of incomplete being, as colours are in the air and the power of the craft is in the craftsman's tool, which may properly and fittingly be called a 'virtual motion'. So Diego Alvarez, De auxiliis divinae gratiae, book 3, disputation 19, who defends this last opinion as true and as his own.
Latin
XLVIII. Licet enim omnes illi efficax istud auxilium nomine praedeterminationis physicae significent, & dicant esse gratuitam & praeviam Dei motionem, quae voluntatem creatam movet & applicat ad bene operandum; nonnulli tamen sunt qui dicunt praemotionem illam Dei qua voluntates humanae ad bene agendum moventur, se habere ad modum qualitatis non permanentis, sed transeuntis cum operatione voluntatis ipsius. Alii vero dicunt motionem actualem qua Deus movet & applicat voluntatem ad operandum, esse realiter ipsam voluntatis operationem, quatenus procedit a Deo, voluntatem ad agendum applicante & praemovente efficaciter. Denique alii pertendunt motionem illam praeviam, nec se habere ad modum qualitatis in voluntate receptae, nec esse idem cum ipsa voluntatis operatione; sed aliquid quod habet esse quoddam incompletum, per modum quo colores sunt in aere, & virtus artis in instrumento artificis, quod proprio & convenienti nomine dici potest motio virtuosa. Ut apud Didacum Alvarez videre est lib. 3. de Auxiliis divinae gratiae disput. 19. ubi postremam hanc sententiam tanquam veram & suam tuetur.