Do We See Through Telescope but not through Microscope

Van Fraassen as an empiricist believes that ‘observation’ is perception of something without instruments. On the other hand¡ as a constructive empiricist¡ he adds a constraint based on which if something is observable does not automatically imply that its observing conditions are ready now. Considering moons of Jupiter as observable entities and electron as an unobservable entity¡ he believes that we do not see the ‘electrons’ atomic theory shows us by microscope. Realist critics of van Fraassen without considering mentioned restriction and based on different reasons give examples such as extra solar planets and claim if we count these entities as observable entities we have to count electron as an observable entity as well. However¡ in this paper¡ based on the criterion of ‘existence or non-existence of observable reference by naked eye in suitable conditions’¡ which meet for all of the critic''s examples¡ but does not meet for electron¡ we will argue¡ as van Fraassen has claimed¡ for counting electron as an unobservable entity