Within the layers and spheres described in Hartmann's architecture for critical ontology there is scope for introducing further structure. A Field of Sense [1] is an organisational concept that can be employed within a layer or within a sphere. It will be seen below that within the critical ontology adopted from Hartmann that Gabriel's full ontology cannot be accepted but a Field of Sense remains as a useful structure.
A Field of Sense is a domain in which objects appear in relationship to each other. How objects relate to each other depends on the properties that they have. Take, for example, the tendency for a cube of ice to melt while lying on a table in a warm living room. In this example, the living room is a Field of Sense in which the table, the warm air and the ice cube appear. The living room itself can in turn be an object in a Field of Sense such as a house. In `the house' Field of Sense the living room can have the properties of being warm and having a table in it.
For Gabriel the mode of existence of an object and its properties depends on the Field of Sense that grants that mode. In that ontology, to exist is for something to appear in a Field of Sense, roughly; to exist is to belong to a domain in which objects appear.
The notion of sense here is developed by Gabriel from that of Frege [2], whose use of `sense' is close to grasping the meaning of the term when restricting considerations to a concept. It is generalised by Gabriel to grasping how an object appears in the context that makes that appearance possible. This grasping is generalised further to being affected by the appearance of an object. This form of `grasping' need not be cognitive. To use the example Frege employs; the morning star and evening star are two senses of the proper name Venus. Frege uses epistemological terms, but these can be reinterpreted ontologically, as follows. The existent thing, Venus, can appear in two senses, as the morning star and as the evening star. There are, of course, many other ways for Venus to appear. The object Venus viewed from the earth in the morning is the morning star. The morning star exists. Existence for Gabriel is not found immediately in the world but in one of many domains. Such a domain is a Field of Sense. There are many such domains, a potentially uncountable infinity. Things make sense and are sensed in such a domain.
For Gabriel the world (the systematic totality of all that exists) is the Field of Sense of all Fields of Sense. His negative result (that the world does not exist) depends on this notion. The Field of Sense ontology may be organised compactly as follows,
- Existence implies that properties appear in a Field of Sense
- A sense is the way in which an object appears.
- A Field of Sense can be an object in yet another Field of Sense.
- A Field of Sense must contain objects and cannot consist exclusively of a single object because an object could not then appear because appearance is always in relationship to something.
- The world cannot be an object in a Field of Sense otherwise it would appear in a field larger than the world.
- But to exist is to appear in a Field of Sense.
- Therefore, The world does not exist.
- The physical universe, people, scientific theories, characters in novels, and films all exist in at least one Field of Sense.
- Fields of Sense are differentiated by reference (as developed by Frege [2]).
- Reference enables recognition of the Field of Sense in which objects are appearing. For example, it would be a reference mistake to identify your family life with a TV play, but it would not be a reference mistake to use it as a metaphor.
Although this has a form of a useful and in many ways enlightening organisational scheme it assumes that existence implies appearance or even the stronger claim that existence is appearance [3]. Although all objects of interest to physical science will appear in a Field of Sense there is no compelling reason to think that all entities must appear in a field of sense or that appearance exhausts what is meant by existing. There may be entities that are inaccessible, that leave no trace. There may be entities that have no scope to appear per se and the world, as the systematic totality of all that exists, is a candidate to be such an entity. From these considerations a modification of the scheme above is proposed:
- The properties of all objects appear in a Field of Sense
- A sense is the way in which an object appears.
- A Field of Sense can be an object in yet another Field of Sense.
- A Field of Sense must contain objects and cannot consist exclusively of a single object because an object could not then appear because appearance is always in relationship to something.
- The world cannot be an object in a Field of Sense otherwise it would appear in a field larger than the world.
- But to be an object is to appear in a Field of Sense.
- Therefore, the world is not an object.
- The physical universe, people, scientific theories, characters in novels, and films all exist in at least one Field of Sense.
- Fields of Sense are differentiated by reference.
- Reference enables recognition of the Field of Sense in which objects are appearing.
So, the headline result of Gabriel's ontological analysis (The World does not Exist) is gone and replace by "The World is not an Object". This is not in any way paradoxal because an entity becomes and object in relation to another outside entity and for the world there is no such entity.
Fields of Sense allow aspects of ontological investigation to be pursued within and across Hartmann's strata and in in both ontic spheres.
[1] Markus Gabriel. Fields of Sense. A New Realist Ontology. Edinburgh University, 2015.
[2] Gottlob Frege. Funktion, Begriff, Bedeutung: Fünf logische Studien. Ed. by Günther Patzig. Hubert & Co, 1962.
[3] Markus Gabriel. Fiktionen. Suhrkamp Verlag, 2020.