Is Not Tho? Or Sensing?

The first thing that we know is ourselves. We know what sensing is, at least in a confused way, because we ourselves sense. It's not possible to define sensing in terms of something better known. So aristotle attempts to define it partly in terms of what it's not. A coal heats a poker. I think that aristotle means to contrast sensing with a purely physical change. Can we talk about plants that belong to two categories, sensing and nonsensing? Thank you very much.