Peirce, On a New List of Categories, § 2
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§ 2. This theory gives rise to a conception of gradation among those conceptions which are universal. For one such conception may unite the manifold of sense and yet another may be required to unite the conception and the manifold to which it is applied; and so on.
Peirce, On a New List of Categories, CP 1.546, CE 2.49