thinking

[1]	thought , thought process , cerebration , intellection , mentation
[2]	opinion , judgement , belief , thought , point of view , viewpoint , assessment , evaluation , theory , reasoning , conclusion , idea , philosophy , outlook

adj.

[1]	rational , sensible , ratiocinative , intelligent , reasoning , reasonable , meditative , contemplative , reflective , philosophical , cogitative , pensive , thoughtful , intellectual
[2]	intelligent , reasoning