 Price’s book, Perception (1932), is an especially probing account of sense data, their ontological status and cognitive role. He begins by isolating a sense datum as what is given in perception such that we cannot doubt its existence: the extant bulgy patch of red that occurs when a tomato is viewed in good light cannot be doubted, even if we can doubt whether we are seeing a tomato or indeed any physical object at all (1932: 3). The bulgy patch is directly present in consciousness, that is, is “given” as a datum by means of a relation of mental acquaintance. Price, as has been mentioned, recommended that the term “sense data” should be considered, in its meaning, neutral on ontology. But he went on to argue for a specific conception of what sense data are, including a specification of their cognitive status and their ontology as a tertium quid.