Ontological realism in philosophy is the idea that objects exist independently of their behavior and relationships. Realism in this sense means that the objects in question and their relationships are real and do not depend on our beliefs and opinions. According to ontological realism, the truth of any statement about the relationship of an object, for example, «the table is actually a table,» does not depend on the person’s beliefs about the table, for example, «a table is probably a chair» or a person’s opinion about the relationship of a table to a chair, for example part of the table, «or even the relation of a chair to a table. For example, whether a person is sitting at a table depends on the statement «the table is the table,» which is a real statement. Ontological realism is usually associated with the positions of logical positivists. This school of thought emerged in the mid-1800s as a reaction to Cartesianism, which dominated the philosophy of science at the time.

Bennett argued that in accordance with ontological realism, people cannot know about objects or their relationships, because the logical consequences of this will be contradictory, that is, the very concept of «truth» (as opposed to an opinion or assumption), going beyond the phenomenal world, is impossible… For example, people cannot know about a table, and therefore the very concept of a table is beyond experience. The logical consequence of this fact is that the right to deny the existence of an object cannot be justified. As Bennett puts it, «if [an object] has no ’informative power’ other than our relationship with the world, then we are able not only to know its truth, but also to insist on its truth with thoughts, our own and others». The logical consequence of ontological anti-realism is that ontological statements about the world are invalid.

Bennett attributes ontological antirealism to logical positivists. For Bennett, positivists questioned the idea that a statement about an object’s relationship, such as «a table is actually a table,» is also a statement about that object, which Bennett calls an «ontological» statement. According to Bennett, ontological statements are too «abstract» to be true. For Bennett, an ontological statement about an object must represent the state of affairs with an object and must be able to justify a statement about an object. Thus, from Bennett’s point of view, a statement about the relationship of an object, such as «a table is actually a table», is also a true ontological statement, but its truth is incompatible with the truth of another ontological statement concerning the same object, that is, its relation to chair. Because of this incompatibility, statements about this object cannot be true if both statements are not true, which would be incompatible with the true nature of the object.