When our knowledge about a particular thing is extended by a new attribute or relation of which we are sure that the thing concerned has it, this normally is a further determination of its nature for us. The class of predicates for which this does not hold is that of 'nondeterminative predicates'. Take, for example, being a thing (or being-a-thing). This is an 'attribute' every thing in the domain of discourse has. Being part of the universe cannot even be an attribute and is also conceptually nondeterminative. Being classifiable and collectable (in a set-theoretical sense) are of the same type. Being itself (regardless of domain) or being a thing (in a particular domain) is the common denominator for all nondeterminative 'attributes' of this kind. Strictly speaking, there is only one 'attribute' of being or existence: existentiality. This is what all (existing) beings (which are things in some domain) have in common. (As existence is something all beings have in common --predicative or nonpredicative, primary, secondary or whatever-- it is nonsensical to suggest that existence or existentiality would be a first-order predicate or that it would be of any other, definite order. Typical of existence is precisely that it is of no particular, predicative order.)

A thing must always have 'the attribute of existence' if such a universal pseudo-attribute is conceptually recognized. It is something else, however, whether the idea or concept of a thing denotes something in reality and whether a conceptual combination of predicates, or predicates and parts, is a real thing (rather than a mere set collected by its creator). The thing one has in mind may, then, be an object or other nonbasic thing, it may also be a predicate. Imaginary things (such as gods, demons and other supernatural 'beings') are but too often saddled not only with impossible combinations of predicates but also with impossible predicates.

Attributes and relations which are predicated of a thing while thinking about it, and which the thing would not have if it were not conceived of, or had not been conceived of, are a mere result of a person's own reflections on the thing in question. The name we shall use for this type of nondeterminative predicate is reflectional predicate. Reflectional predicates are not determining for the things considered but for the considerations, thoughts or reflections themselves. Being thought of is a reflectional predicate, and so is being denoted by an atomic expression in the language. (Other examples have already been mentioned in 1.7.2.) Whereas, theoretically, universal attributes such as the attribute of existence belong to all (real) beings, members of the subclass of reflectional predicates belong only to a certain category of things. Thus being-collectable may be a universal attribute, being-collected (in a general, set-theoretical sense) is a reflectional predicate. And when collecting is used in a concrete, everyday sense being-collected is even a determinative primary predicate (or rather pseudo-predicate, as we will see).

To decide whether or not 'two' things are identical, one cannot look at their universal attributes, because those attributes are precisely what they are supposed to have in common as beings or as things in the domain in question. And, altho one could, one must not take their reflectional predicates into account either when discussing the possible identity of 'two' things. Even to be able to pose the very question itself one must have given the 'two' things different names or descriptions to start with. But 'having-the-name-a' or 'having-the-name-b' is a reflectional attribute which is not determinative for the thing, nor is 'being-written-' or 'having-one's-name-written-on-the-left-hand-side' and 'being-written-on-the-right-hand-side' with respect to, say, a sign of equality (a = b). It is but too easy to confuse distinctions in one's own reflections on reality with distinctions, or rather the lack thereof, in reality itself. Of course, distinctions in our thought are also distinctions in reality. But then, they are distinctions in a sort of propositional reality, not in the reality the thought is about.

Like universal predicates, reflectional predicates do not belong to any predicative order either. They cannot be classified as first-order (being only the predicate of something that is not a predicate itself), second-order (being only the predicate of a first-order predicate) or higher-order, because they simply are not real predicates of the thing conceived of. In reality they stand for a predicate of the thinker 'imself, or of 'er thought, and as such they are of the first predicative order but not as a reflectional attribute or relation of the thing thought about. Whereas universal and reflectional predicates belong to the category of nondeterminative predicates, it is the category of determinative predicates in which we find the primary, secondary and higher-order predicates we have already been acquainted with.