879. I have demonstrated two things:
1. Sensation is in us, not in external agents (cf. 632 ss. and 672 ss. ). The idealists misused this fact. I grant them its truth, but they should not have neglected other facts while acknowledging it. Their error was the result of insufficient observation, not of defective observation.
2. Sensations are in us as the term of actions done by something other than ourselves (ibid.).
This was the other fact neglected by the idealists, although no less clear than the first. In every sensation we experience a passive modification or disturbance within us, of which we are directly conscious which expresses the term of an external action. By their nature, therefore, sensations, although in us, inform us of something outside ourselves. We must either deny the difference between activity and passivity, or accept that to be conscious of an experience in us is to be conscious of an action done in us, but not by us.
Antonio Rosmini, New Essay concerning the Origin of Ideas, Volume 2, Part 5, Chapter 11.