Ultimate Reality / Truth, Conventional Reality /Truth, Illusion and Delusion. Ultimate Reality: Ultimate here means in the ultimate, highest and undistorted sense. Or it means that which comes within the sphere of knowledge that is highest and ultimate. Reality is defined by the fact of it having characteristic, function, manifestation and proximate cause which forms the foundation of such knowledge. Conventional Truth: Product of the thought process whose status must be only as a ‘concept’. Concepts do not have any characteristic, function etc. which can be a basis for the kind of knowledge stated above. But any analysis must only happen by reference to yet other concepts and result in more of the same. There are of course concepts which point to ultimate realities and those which do not. Of the latter, there are those whose reference point is based on the experience through the five senses and those that are purely abstract. However in all cases, they are to be distinguished from the ultimate realities. Illusion: All concepts can be said to be illusions. However, some being the product of real experiences through the five senses, can be referred to without risk of becoming deluded. Indeed they are necessary to function in the world and also to learn about the Truth. However this does not make them anything but illusions. Delusion: When illusions are taken for being ultimately real, it becomes delusion. “The ‘round earth’ is concept, illusion, conventional reality but not a delusion.” I believe that there is more to say, however presently nothing comes to mind. But it’s your turn now Tejwant ji and Findingmyway ji, to comment.