But the reality-producing functions of the mind are two, and they act jointly. The same manifold that is regarded as the scene of irreducible manifoldness, is also regarded _sub specie unitatis_. The immense practical importance of holding fast to diversity as indefeasible, and at the same time stressing the unity, will amply appear in the course of the third Book. It is this insistence on the two aspects _jointly_, that distinguishes the theory here worked out from preceding ethical philosophies, and will be found to open new ethical applications to conduct. It is this insistence on the joint action of the two reality-producing functions that will enable us to see in the ideal of the whole _a pattern traced_, and to derive from this pattern of relations a supreme rule of conduct. If the differences that exist among the members of the manifold be slurred over, if the indefeasible singularity of each member be overlooked, if the many be derived from the One, since the One is an empty concept, we shall gain no light upon the conduct to be followed by each of the many. It is true that our notion of the distinctive difference or the uniqueness of each ethical unit is also empty as far as knowledge goes. The unique is incognizable. Yet we are able to apprehend, and do apprehend, a determinate relation as subsisting between the ethical units, and this relation supplies us with an ideal plan of the ethical universe and a first principle and rule of ethics. The relation is that of reciprocal universal interdependence. Consider that an infinite number of ethical entities is presented to our minds—each of them radically different from the rest. In what then possibly can the unity of this infinite assemblage consist? In this—_that the unique difference of each shall be such as to render possible the correlated unique differences of all the rest_. It is in this formula that we find the key to a new ethical system, in this conception we get our hand firmly on the notion of right, and by means of it we discover the object which Kant failed to find, the object to which worth attaches, the object which is so indispensable to the ideal of the whole as to authenticate unconditional obligation or rightness in conduct with respect to it. It is as an ethical unit, as a member of the infinite ethical manifold, that man has worth.[31] In accordance with the above, the first principle of ethics may be expressed in the following formulas: A. Act as a member of the ethical manifold (the infinite spiritual universe). B. Act so as to achieve uniqueness (complete individualization—the most completely individualized act is the most ethical). C. Act so as to elicit in another the distinctive, unique quality characteristic of him as a fellow-member of the infinite whole.