“Philosophy, as I have hitherto understood and lived it, is a voluntary living in ice and high mountains… from the lengthy experience afforded by such a wandering in the forbidden I learned to view the origins of morilizing and idealizing very differently from what might be desirable: the hidden history of the philosophers, the psychology of their great names came to light for me. How much truth can a spirit bear? How much truth can a spirit dare? Error, a belief in the ideal, is not blindness, but cowardice… Every acquisition and step forward in knowledge is the result of courage, of severity towards oneself… Nitimur in vetitum: in this sign my philosophy will one day conquer, for fundamentally what has hitherto been forbidden has never been anything but the truth”
Nietzsche – Ecce Homo
NB: featured image is Nicholas Roerich’s ‘Kanchenjunga’ (1936). ‘Nitimur in vetitum’, meaning ‘we strive for what is forbidden’, comes from Ovid’s Amores which rather tellingly depicts the Garden of Eden. Here Nietzsche exemplifies his anti-idealist views (idealism = reality is nonexistent and unknowable outside of human perception / nothing is knowable outside of the mind). Moreover he once said that ‘idealism is untruthfulness that has become instinct, a not-wanting-to-see reality’. Perhaps Nietzsche’s primary reason for rejecting idealism is simply that it goes hand in hand with the relinquishment of a fundamental aspect of knowledge and truth, and is at its core an admittance of defeat, even (as he says above) a cowardly act which exposes some underlying fear and anxiety when it comes to confronting truth. Plato’s idealism is the archetype for such, and has always been, epitomised by the shadows which were cast on the cave wall – and for Nietzsche idealism is somewhat to remain confined to or even reside purely within shadow. The idealist says “I can and will only ever know what is on the surface, what is shadow, yet I know that there is something beyond that, and it this beyond which is of the very highest significance, and comes before all else”. To strive for what is forbidden is surely not to be read as some advocacy of mathematical truth or hard-science (in fact Nietzsche expressed in Human All Too Human  that hard science is often the result of a ‘belief that truth has been found out’ due to the false belief which language imbues in setting up ‘a seperate world beside the other world, a place it took to be so firmly set that, standing upon it, it could lift the rest of the world off its hinges and make itself master of it’. Mathematics also falls into this category, in that, as Nietzsche states, in nature there is ‘no exactly straight line, no real circle, no real magnitude’, it is simply a frame of human logic placed atop reality by which we are to navigate it. Do not misread this as some dig against hard science and mathematics, Nietzsche did not reject the joyous science of his day. Rather here it is much more a delving into the roots of truth, much like Foucault’s [a key follower of Nietzsche] distinction between episteme and archaeological knowledge – archaeological knowledge being that which is passed on and based on the assumptions of forebears, and episteme being knowledge which is proveable outside of history. Perhaps you could argue that Nietzsche is arguing idealism as the metaphysical equivalent of limiting yourself to purely archaeological knowledge? The ‘severity’/’cleansing’ towards/of oneself Nietzsche talks of is essentially then the stripping away of these restricting idealist views. On a side note: consider mathematics as a frame which works moreso on the level of optimisation, a perfect frame atop imperfect reality, which can measure the projected velocity of a meteorite as hard science but can never truly equate reality. Bertrand Russell said that ‘mathematics can never tell us what is, but only what would be if…” [History of Western Philosophy, p. 139]). Rather, this strife is for a philosophy which pushes into this beyond, into that which casts the shadows, and this is a task which surely requires one to push their sanity to its very limits… is madness the crucial means of reaching this higher knowing? And if so, did Nietzsche find the key to this knowledge?