In the first chapter of the fourth section of his al-Isharat, Avicenna, relying on the common nature of material things, presents an argument against materialism, which has been focused on by later thinkers. In this argument, the negatively conditioned nature is confused with the unconditioned nature. What is available with material examples is the unconditioned nature that is plural and material and what is immaterial is the negatively conditioned nature which is not available along with the instances of nature.
     Relying on Avicenna's words, this article tries to explain this argument in a manner that may not be prone to this objection. According to the author, Avicenna wants to falsify the epistemic and methodological foundations of materialism through showing the inefficiency of senses in perceiving sensible natures. Material things include an immaterial nature. When Avicenna says that nature is not sensible he does not intend to say that it is not sensible ontologically. Instead he intends to say that it is not sensible methodologically and epistemologically.