Looking at the world from the standpoint of the conditioned there is no real unconditioned or so one might imagine (an absolute unconditioned medium from which conditioned things arise). This is further to imply, there is no evidence of the unconditioned in terms of the conditioned which might prove to those who are skeptical there, indeed, is the unconditioned.
From Zen’s perspective, the unconditioned can only be arrived at by the complete cessation of the conditioned this being thoughts which make up the conditioned microcosm (mano/manas), i.e., mentation. The world of Zen is an antidote for overcoming the conditioned from a microcosmic perspective; having a sudden and profound glimpse of the unconditioned which is the essence of thought.
From this, the fundamental problem Zen faces which confronts each student is to wean them off off of using thought, almost exclusively, to gain access to Zen’s crown jewel. Instead, they must leap beyond the conditioned to gain access to the unconditioned. How this is accomplished for each individual depends on how much they identify with the conditioned, in this case their mental world. They must accept the fact that Zen demands of us a special cognition free from appearance and beyond mentation.
But even this insistence can be easily misunderstood. It is difficult to grasp that thoughts as concepts represent something standing in place of the actual. Our thoughts about enlightenment actually hide it. Even the time we spend trying to see what Siddhartha realized by many hours of seated meditation only serves to obfuscate and confuse our quest.