Why Frege thought it to be "probable" that truth is indefinable

Frege’s so-called “Regress Argument” is closely examined and it is argued that Dummett’s reconstruction of it is not satisfactory. Contra Dummett, the argument does not involve a regress, is not a reductio and not even a strictly deductive argument. Rather, what Frege tries to show is that any attempt to define truth fails to be epistemically fruitful and thus misses the very point of analytic definitions of concepts. The cause of this epistemic sterility is an inherent circularity, and it is in view of this defect that Frege suggests that truth is very likely so simple that it cannot be defined at all. This circularity, in turn, is due to the fact that Frege takes the sense of “true” to be a constitutive part of the content of acts of thinking a complete thought. Finally, I trace Frege‘s belief in this omnipresence of the sense of the word “true” in thought to his conception of judgment and suggest that it may very well be false