174. Advertence is the act by which the mind gives attention to something. It is of two kinds: (a) full advertence, when there is nothing to impede perfect attention, as when a person is wide awake, in full possession of his faculties, and not distracted; (b) partial advertence, when there is something that, prevents entire attention, as when a person is only partly awake; or not entirely conscious, or distracted with many things. 175. Hence in the following cases, even though there be serious matter, a sin is not mortal, on account of lack of full advertence. (a) When without one’s will there is no full advertence to the act itself, as happens with those who are half-asleep, or who are under the influence of drugs, or who are mentally confined by anxiety or physical pain, etc. (see on Human Acts, 24 sqq.). (b) A sin is not mortal when there is no full advertence to the sinfulness or to the gravity of the act. Those who through no fault of their own are unaware that an act is sinful, or that it is a mortal sin (e.g., children, the half-witted, or the uninstructed), have no full advertence to the malice of the act; likewise, those who, without being responsible for their inadvertence, do not think at the moment of the sinfulness or seriousness of what they do (e.g., those who think out plans for revenge before they have taken second thought on its immorality). 176. Signs that indicate that there was no full advertence are: (a) if afterwards one can scarcely recall what happened; (b) if shortly afterwards one cannot be sure what was one’s state of mind at the time.