 If the argument for the self-establishment of the epistemic instruments is not successful, the remaining option is to argue that the instruments and objects mutually establish one another. Assume that I see an apple on the table. The existence of the apple, the epistemic object, is established by the epistemic instrument which is perception. But we could equally argue the other way round: that the object known establishes the epistemic instrument. This would invite the immediate objection that we then need prior cognitive access to the object known, and if we have this we must already have established the epistemic instrument. We are therefore pointlessly establishing it twice. But if we somehow gain this access without relying on the epistemic instruments the whole project of establishing these instruments seems futile, since it is precisely the justification of our instruments used in gaining knowledge of the world that we have set out to scrutinize. We will therefore need a different argumentative strategy to argue for the mutual establishment of objects known and epistemic instruments, and in particular for the establishment of the latter by the former. One way of going about this (which does not commit us to the viciously circular mutual establishment criticized by Nāgārjuna) is to argue that because the epistemic object is perceived, there must be something bringing about such a perception, and this is the epistemic instrument. In this case the apple establishes the existence of the epistemic instrument by which it is known. An essential prerequisite for this latter direction of establishment is of course success. Because we successfully apprehend an apple our means of apprehension is regarded as an epistemic instrument. If we were susceptible to frequent apple-hallucinations that disappeared once we tried to touch them we would not regard perception as a reliable apple-detector, that is, as an epistemic instrument. But since we are generally successful in our cognitive interactions with the world and normally only perceive the existence of apples that are indeed there the very fact that we successfully apprehend a world of outside objects serves as an argument for regarding the successful means of apprehension as epistemic instruments. An immediate difficulty with this procedure is that we also need an epistemic instrument for establishing the success of our cognitive actions, that is to ascertain whether we really are perceiving the apple or just an apple-hallucination.