I argue that the best way to understand Donald Davidson’s notion of triangulation is as an account of the concept of objectivity. In particular, triangulation is the framework that makes possible the simultaneous emergence of the interrelated concepts of objectivity, belief, truth, and error, as well as determinate mental content and linguistic normativity. I argue that this framework consists of the shared similarity standards and shared similarity responses of two creatures converging on a common object and the responses of one another.
I claim that Davidson’s introduction of the notion of triangulation was motivated by the problem of error in interpretation and the related epistemic problem of objectivity. I also claim that the notion of triangulation grew out of theses inherited from his mentor W.V.O. Quine as well as work Davidson did in the middle part of his career both on the causal determination of content, and also on the rejection of linguistic conventions and his alternative account of linguistic normativity. I suggest that Davidson’s work on the notion of triangulation went through roughly three periods of changing focus: its role in making possible determinate content; its role in making possible the concept of error; and its role in making possible linguistic normativity. All three roles are required for emergence of the concept of objectivity, and all three require actual linguistic communication with another creature.
Finally, I argue that Davidson’s solution to the problem of objectivity is to be seen is his final account of interpretation. That account of interpretation was a confluence of his account of linguistic normativity and the way in which triangulation makes such normativity possible in the context of ostensive language learning. Davidson came to see ostensive learning not as the adult teaching the child a preexisting language, but rather as the adult providing the normative check needed for the child to develop a new language of its own. The adult’s ostension of an object establishes the content of the child’s new bit of language and the object serves as the objective standard against which the adult judges the child correct or incorrect in future uses of the language thus created. Davidson came to see interpretation to involve the same process of ostension, with the native providing what is necessary for the interpreter to create a new language similar to that of the native’s. The native’s utterance of an observation sentence provides the ostension that makes objects constitutive of the interpreter’s newly created sentence and this relation between sound and object is the source of our sense of objectivity.