  Wolff next defines clarity and distinctness and indistinctness in cognition. Thoughts are clear “when we know well what we think, and can distinguish that from other things”; they are obscure if we cannot even distinguish the objects of our thoughts from other objects (German Metaphysics, §§198–9, p. 188). Clear thoughts are also distinct if we not only know what objects we are thinking of but if “our thoughts are also clear with respect to their parts or the manifold that is to be found in them” (German Metaphysics, §207, p. 194), and are otherwise indistinct or confused. Wolff then defines sensations (Empfindungen) as those thoughts “which have their ground in the alterations of the members of our body and which are occasioned by corporeal things outside us,” and the “capacity for having sensations as the senses” (German Metaphysics, §220, p. 202). He then adopts Leibniz’s view that sensations or sensory perceptions are typically clear but indistinct or confused (German Metaphyics, §214, p. 198). Unlike Leibniz, the systematic Wolff observes that sensations come in differing degrees of clarity (German Metaphysics, §224, p. 206), but they are nevertheless all indistinct to some degree. This means that at least in principle a purely intellectual or conceptual representation is always a better source of knowledge of its object than is a sensory representation of it.