It is in consideration of the details chronicled in verses 22ff that it becomes very obvious that the dead, both righteous and wicked, are conscious. Perception involves an awareness of objects, hence, consciousness. It implies that Lazarus was in a warm and respected fellowship with Abraham. Clearly, this indicates consciousness. Communication - The rich man could both speak and be spoken to.
Communication is possible only with conscious beings.
The suffering rebel had not been annihilated. Recognition - The rich man recognized Lazarus and requested his services by name. Recognition involves consciousness. Comprehension - The rich man made two requests of Abraham. First, he asked that Lazarus be permitted to dip his finger in water in order cool his parched tongue.