It is an ancient question. It is a question about “Whether non human animals feel like us?”
I ask a similar question: “Do other humans feel like you do?”
There are no means to know it. No means.
All you can do is to interpret the feelings of others and try to relate to them or act towards them in a most meaningful manner; but you cannot ever know what exactly others feel like! You cannot be the ‘other’, even if you have this Neptunian ability of dissolving your boundaries temporarily; you cannot feel how ‘others’ feel.
You may very well ask me: “We relate to and respond to the feelings of others and we do not really need in many cases, to literally ‘become’ ‘the other’ in order to help them in the best possible manner.
Yes, you’re right.
Many times it is being ‘detached’ which helps others, because, having the same feelings (or similar feelings) will make you confused. It might be even better to get into the shoes of others (for a while!) and then, having understood the gravity of situation, become detached and find a solution to help them out. Now: while getting into the shoes of others, if you could feel exactly like they feel; if you could become, even for a minute, what they really are; you might find the most adequate or fitting solution for their condition.
A hypothetical scenario:
A man comes to me and he is in deep despair. He says: “I am in pain and agony.” To give me a hint about the ‘degree’ of pain he is going through, he suggests: “Life is hopeless; I am willing to commit suicide in a minute.” Now: As I try to relate it to the situation where I will be so helpless and dejected that committing suicide will be the only refuge; I realize: It is not necessary (in fact it is a very remote possibility) that the degree of pain at which I prefer committing suicide over living, is, as same as his degree of pain at which he is very willing to commit suicide. This is, in my opinion, the core problem of Psychology: quantification of feelings-because measurement and comparison is not possible.
Who has been hurt more, me or him? Always remains the question in relationships.
How good your child feels is, key in their upbringing. How good your old parents feel, is key to harmony and how good you feel is key to peace.
When, you are in a dilemma and you have to take a decision to help one of the two persons based on the degree of their suffering, you cannot easily decide and your decisions might often be wrong in the absence of such discretion