Abstract
Is identity fundamental to formal systems? Even if a system have no the identity relation, is
that concept is not assumed in any way – whether in a metalinguistic or intuitive level? In this
paper we shall discuss this issue. Otávio Bueno (2014, 2016) argues against the elimination of
identity, holding that this concept is fundamental and non-eliminable (even in does systems
that claim to do so). Décio Arenhart Krause and Jonas (2015), by the other hand, have a
number of objections to Bueno’s thesis. Firstly, we look at how the concept of identity was
accounted in the philosophical tradition, as well as part of its formal account. We will also
examine the notion of indiscernibility that, according to the traditional approach to identity,
is equivalent to the notion of identity, but (arguably) is not it logically equivalent. Thus, we
shall state Krause and Arenhart’s strategy, according to, in a formal system we can eliminate
identity in favor of the indiscernibility notion. Finally, we shall expose Bueno’s criticism to
such strategy, and then to put forward some objections against it.