From a scientific point of view, losing a part of your conscious would make you the lesser person (since your conscious is what makes you "you"). Now one might say that you would still have full human value even if you were to lose a part of your conscious. But if you were to be completely dead right now (lose all your conscious functions), would you then still be considered a full human being? Or would you then be considered as the lesser person now? I think you would obviously be considered the lesser person. Therefore, to lose a part of your conscious is the very essence of dying without actually being dead. Therefore, you would be a lesser person if you were to lose a part of your conscious (such as if you were to lose your ability to experience pleasure due to depression or emotional numbness). It doesn't matter how much others value you, what great things you do in life, and how much you helped others. The scientific fact is that you are still the lesser person no matter what. Unless, of course, your brain fully makes up for that loss in other conscious brain areas. But it must fully make up for that loss. Otherwise, you would still be considered the lesser person.
Also, if you are going to say something such as that we are constantly changing and that, because of this, we can't compare things to other things and such, although you are right that we are all constantly changing and such, we can still compare because time itself can be split up into individual units. The smallest units of time possible are all units in which we can then make the comparisons if we develop the technology in the future that can make comparisons based on each individual unit of time. You would compare yourself to others, your former self, as well as who you would be without that loss based on each individual unit of time.
The words "more" and "less" are words that have an objective meaning in science. If something gains function, then it's obvious that thing has more function. If this thing loses some function, then it obviously has less function. Therefore, since who you are as a person is all your conscious brain functions, if you were to lose any one of these functions (such as your ability to experience pleasure due to depression or emotional numbness), then that would make you a lesser person compared to who you were before with at least more conscious brain functioning and in comparison to others who do have more conscious brain functioning. But since who you are as a person is only your conscious brain functioning and not your body, having a physical disability would not make you a lesser person. But as long as your brain is unable to fully make up for that loss of pleasure in other conscious brain functions, then you will remain as the lesser person. There are such people whose brains cannot fully make up for such losses because, as I've explained before, everyone is different and not everyone's brains will be able to fully make up for these losses. So these are the types of people who would remain the lesser people.
As for value and worth, it is our brains that give value and worth to things and value and worth is something that is defined by how much conscious brain functioning we have since it's, again, our conscious brain functions that generate value and worth in the first place. For example, if you find great value and worth towards something, that would obviously mean that the functions in your brain responsible for perceiving value and worth towards those things is highly functional. But even so, if you were to lose a part of your conscious and you were to say something to yourself such as that: "I may have lost this part of my conscious, but my life now has much more value and worth than before since I have now decided to do great things in my life and help those who are suffering from this same loss," this can either be true or false. If the functions of your brain responsible for perceiving value and worth does not make up for what you have lost in your conscious, then your life would actually have less value and worth and it would be delusional for you to somehow think that your life has more value and worth because only brain functioning itself exists. The concepts that are perceived separate from our brain functioning does not exist (i.e. concepts such as that we are somehow better and stronger people with more worthwhile lives despite our loss of conscious parts of the brain and despite the fact that our brains did not fully make up for that loss in other conscious parts of the brain). However, if your brain fully makes up for the loss, then your life would have the same amount of value and worth as you were in the past when you did not have such a loss of brain functioning because the amount of brain functioning that you have now as opposed to before your loss is now the same (just different due to the fact that another part of your brain has made up for the loss). And if your brain even goes further beyond making up for that loss in other conscious brain areas, then your life would have more value and worth than ever before. As for a given example here of two people who have not lost any conscious brain functioning and have both found value and worth in life and which one of these people would be more of a person with a life of greater value and worth, it still all comes down to which one of these people has the greater amount of conscious brain functioning. But if they were to somehow have the exact same amount of conscious brain functioning overall, then they would both be of the same status and their lives would both have the same value and worth.
Finally, here are some quotes from people I have addressed so far:
How did you formulate this definition of consciousness? What evidence supports your position? You could argue that when people sleep they temporarily lose a part of their consciousness. Does that make them lesser beings? Of course not.
It would in that given moment. But since the brain is, I'm sure, able to fully make up for that loss upon wakening, then when the person is awake, they would be back to being a full person. But, again, if it's a loss that the brain cannot fully make up for in other conscious brain areas for your entire life, then you would be the lesser person for your entire life.
A second flaw I find in the argument is the concept of lesser and greater people. Several years ago I lost total hearing in my right ear; with medical help and the miracle of self healing I gained about 45% of the hearing back. As a result of that hearing loss, I have gained a level of empathy I never had with regard to hearing loss in other people. So on the one hand I am a "lesser person" because of my hearing loss. But on the other hand I am a "greater person" because I have a greater understanding of people with hearing losses. (I believe that this has also extended to other physical disabilities.)
So how do those two changes balance out? Am I a net better person, or a net lesser person?
It's all just a matter of conscious brain functioning and nothing more. So if what you have lost (in this case, the ability to hear which is a part of the conscious since it's your conscious that has the ability to hear) is not fully made up for by empathy (which is yet another conscious brain function), then you will remain the lesser person.
One huge exception I have with the logic is the concept that people can be reduced to one value upon which their "greatness" or "lessness" can be measured. I believe that we all have many dimensions that can be measured.
For example, one could talk about physical strength as one such dimension, but then does that mean upper body strength or lower body strength, does that mean single exertion power, or endurance? There are dozens of exercise machines in a gym, so I would propose that there are several strength dimensions per each machine. Thus even strength can not be measured by a single value.
It can because it all just comes down to quarks and leptons which is something that makes up all matter and energy (something that all matter and energy has in common).