Joe, I do not "know" that "purity" does not exist empirically. As a negative it cannot be proven to be so everywhere and throughout time, obviously. I mean to say that the concept is invalid: purity, like absolute (and perhaps infinity) are metaphysical categories, artifacts of the mind, not entities in the world.
Thanks for responding, JLN
(even though I hadn't directed my question to you), and further thanks for not misinterpreting my query as somehow "hostile."
I'm quite willing to accept that "purity" is unknown in the physical world (every substance will have some
measure of impurity), but when we're dealing with motivations I'm not sure why it's impossible to speak of a "pure" motive. After all, motivations are not physical substances, so they're no subject to physical laws. And if "purity" is a metaphysical concept, such as "infinity," then presumably it, at least, has a place when describing non-physical concepts, such as motivations.
Now, if someone wants to argue that it is psychologically
impossible to have "pure" motives, I'd be interested in learning the basis for such an assertion.
I fully agree with JLNobody that Absolute,Pure or Nothing But etc ., are available in Labs only and not in human Life! All our actions are usually for more than one reason.The only reason among all reasons,that will not change is self interest.
If "self-interest" is the only constant in human motivations, then are you saying that there is no such thing as "altruism" -- either pure or impure?