 One proposed solution to this difficulty involves the notion of ‘seeing as’ (see Nolan 2012, 27–32). Malebranche’s painting analogy is merely a metaphor. Sensations of course are not literally painted onto intelligible extension. In fact, intelligible extension is not altered by our perception of it since, like all things in God, it is immutable. Rather, we see intelligible extension as a particular object, such as a tree or a mountain, even though its intrinsic nature is very different. These different ways of perceiving nevertheless qualify as cases of seeing intelligible extension because, according to the doctrine of efficacious ideas, it causes us to perceive it in these different ways. In fact, when intelligible extension affects our mind with one set of sensations, we see it as a mountain; when it produces another set of sensations in us, we see it as a white-winged bird flying against a blue sky, etc. Malebranche writes: