In any point of dissonance, especially on subjective matters, we get defensive with liners like “Your judgement is yours” or “I'm only responsible for what I say and not what you understand”. This is more so with sensitive matters – like Casteism, rift in your friends’ circle, politics (Telangana agitation) etc. The logic behind these lines is that perceptions are different for different people. For example, you have people who adore Hitler, too; and those who hate him are available by the dozen. I totally dislike Balayya, but there are people who quite fanatically endorse his movies. By these empirical examples, we understand, on one hand, that perceptions are different. A detailed analysis of this variation (and its necessity) can be had here.
On the other hand, we have very common perceptions when it comes to hard-hitting scientific facts. Nobody retorted to their Physics lecturer explaining Newton’s laws by saying “These are your perceptions/ judgements.” When we speak of the Sun, all humans with the faculty of vision will approve of its existence in unison. There are no ifs and buts, and other differing viewpoints. Thus, we find that there are perceptions which are common to us. In-fact with no common perceptions, no scientific discussion can ever be possible.
It seems, apparently paradoxical, that perceptions can be both common and different. It’s not as much of a paradox as it is a mixture of commonality and differences. That is, there are perceptions which are common to two humans, and also those which are not. (Akin to light being both a wave and a particle). To illustrate, we represent perceptions of my friend (Rakesh Mashar) and mine by Venn diagrams in the adjacent figure. The intersection portion has scientific facts and deductions. There are no two contrasting opinions when he and I are in this intersection zone. Quite differently, away from this zone, there are differences. Mashy likes Pawan Kalyan while I don’t. I like classical music while he is not such a big fan.
The million dollar question – What is the use of this entire grind? The analysis has the greatest practical utility. When one uses the rationale ‘Your judgement is yours” in the non-intersection zone, he is being logical. When one does the same in the intersection zone, he is being a hypocrite. One step further: so far the discussion has only been about humans and their perceptions. In the following lines, I try to extend it to all living forms, and take the logical conclusion as it is. All humans/animals with the faculty of vision accept the scientific fact ‘Sun’, but the blind won’t. Similarly, the deaf will not be on board with the barking sounds of dogs. Thus, people deprived of one or more sense capabilities will differ more and more, even in the region of scientific facts. That is, if I were to draw Venn diagrams of perceptions of me and a blind guy, the intersection will not have Sun and so on. Human death is a very bad thing to us and we do not want anyone to die. But a lion in hunger thinks otherwise. Thus, we see that as we include more and more living forms, the intersection part becomes smaller and smaller. Imagine infinite Venn diagrams denoting the perceptions of all living populace – human and others- the intersection part being the point of discussion. With very little thought, it is obvious that only consciousness exists in the intersection part. That is the common ground of all perceptions. That is to say, the very root of all our thoughts and perceptions is consciousness – 'Aham in Sankhya philosophy or Ego'. For an observation to be made, we implicitly assume a conscious observer. The very root of all thought/perception is consciousness. When the Vedantist declares that the abstraction of ‘Existence’ is the only constant thing in this world of constant flux, he is being the most rational. The common ground of all perceptions is consciousness.