A concrete individual is determined with respect to every pair of possible opposing predicates. A thing is only possible insofar as it draws its predictes from this domain. We do not know exactly what all the possible predicates are. But when we form an idea of the sum of all these predicates, we represent an individual, though only an ideal. Of course, such an ideal could only be a thing in itself.
Reason represents it only as a ground of the properties in limited beings.
We have no knowledge of the existence of such a pre-eminent being. This being is not composed of limited being, but is their ground. We can find all the traditional properties of God in the ideal of pure reason, so it is the object of transcendental theology. Transcendental theology is not a legitimate science, as it goes much further than the idea allows. We cannot say that it determines an object, but only that it can be of use in detemining given objects.