Consciousness of non-existent from the perspective of Islamic Philosophy and Husserl's Philosophy

The present paper discusses how apply human knowledge and consciousness about non-existent affairs? How is it possible to believe an non-existent object? This epistemological problem has been raised for Islamic and Western thinkers with different aims and motives, and each of them has come up with the problem by relying on the intellectual and structure of their thinking. The thesis of this paper is that, regardless of the Eastern and Western cultural and social bases, and the stuff and content of the discussion, one can find a similarity in form of the issue between Western and Islamic thinkers. More importantly, the article is not just about finding a mere difference and similarity between thinkers, but, it seeks to survey and study the solutions presented to the discussion. Among the prominent philosophers of Islamic philosophy referred to Ibn Sina, Khaje Nasir al-Din Tusi and finally Mulla Sadra. And after explaining Brentano, Boltzano, Meinong and Husserl's opinions, they will be compared.