Some musings on the intrinsic worth of humans

M Tobis found somehow a twitter thread by someone musing about "humanism", and I also find myself agreeing with part of it.  I won't try to copy all of it, but it starts:

And the bit I am most interested in:

I tend to find comparative religion interesting for the way in which they can construct a motivation for choosing the "pre-rational" belief of human life having intrinsic value.

In many, of course, the idea of an after-life reward is an obvious motivation. 

But going back to this week's topic of Buddhism, I always have had a problem with understanding how it reconciles its teaching about the illusory "non-Self" nature of self and its ethical teaching about that you should treat other "non-Selves" well.   Some pro-Buddhist advocates sell its view of the self as entirely consistent with modern, scientific materialist's views;  but if so, it seems to mean that Buddhism loses the benefit that I see in other religions of providing a "pre-rational" motivation for treating all humans as having value. 

If recall correctly, in Frank Tipler's The Physics of Immortality,  he argued that games theory provides a basis for ethical behaviour being entirely rational (and therefore having no conflict with science) but his views are pretty eccentric, and I am not sure that there is any widely accepted view games theory means the "pre-rational" belief of intrinsic human value is in fact rational (or, perhaps, a necessary conclusion of rationality.)

I have been thinking about this for a long time.   The distinction between "pre-rational" and rational arguments was basically behind a university essay (or was it during an exam?) on Rawls and his A Theory of Justice.  I thought it a very fine effort at providing a rational argument towards what you might call a universal theory of ethics;  but I remained unconvinced that it showed why alternative uses of rationality with harsher conclusions towards fellow humans were not just as valid.   I was still feeling that it didn't really work to show why the "pre-rational" judgement of the value of humans was something that must be adopted.  

I suppose you can take two attitudes towards this - argue that rationality can never resolve the matter, or (like Tipler, or Kant) argue that rationality can lead you to the "right" conclusion about human value.   I am inclined to be on the side of the latter.