We highlighted in this position paper issues on fuzzy reasoning. The paper discusses reasoning application for decision making in medical diagnosis. This is to reason on medical concepts that are viewed on two type ontologies; namely physical and mental. These two types of ontology have been presented to formalize a patient state: mental ontology reflecting the patient mental behavior due to certain disorder and physical ontology reflecting the observed physical behavior exhibited through disorder. Patient observations are reflected on these concepts for similarity calculation that produce decision making based query. We have investigated multi criteria decision making technique to provide better decision on the attributes collected from patient for medical diagnosis. We apply fuzzy AHP (Analytical Hierarchy Process) for ranking attributes related to physical object. In the same time, we apply bipolar fuzzy decision making logic for ranking attributes related to mental objects. The paper highlights these issues as new challenges extending intelligence reasoning of VDS.