   Reid accepts much of the negative side of Hume's view of causation while rejecting Hume's assertions of the import of those negative discoveries. Reid agrees, that is, that we have no sensory experience of the necessitation of an effect by its cause. But this does not imply our ordinary concept of causation is mistaken. Instead, Reid thinks, the concept of causation is not an idea copied from a sensory impression in the first place. Reid's complex thoughts here are tied to perception and the role of sensations in perception. (See 3.2 Reid's Arguments Against Representationalism, above.) For him, sensations never bear resemblance to the qualities they help us to perceive. It is hardly a surprise, then, that the sensory experiences from which our thoughts about causation spring bear no resemblance to the causal relation. But this fact no more undermines our concept of causation than the lack of resemblance between our sensory experiences of ordinary physical objects and those objects themselves undermines our thoughts about such objects. Like our thoughts about objects, our thoughts about the causal relation are genuinely about the causal relation, despite the fact that the sensations from which those thoughts spring, i.e.the sensations of the relation of constant conjunction, bear no resemblance to the relation they lead us to think about. We have no sensations resembling necessitation, and, yet, causes necessitate their effects.