Real taxa => Ranking

[SKÁLA Zdenek]

I do agree with Pierre and would add only a simple note:

pierre wrote:
Some "things" are physically self-delimited out there. [snip]
Some "things" or material systems are not so well delimited. e.g. a social 
group of interacting individuals, during the time they interact... etc.
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Note that even this continuum of "self-delimitation" is more or less a matte of our (human) way of interpretation, of the time- and space-scale *we* perceive as normal since all "things" have intrinsic time and space dimensions. Surely, bacteria would define a 'self-delimited thing' in another way than we do. Hence, even the above noted "continuum of objectivity" is itself subjective; any perception of the reality is at the same time a kind of interpretation. So, searching for objective criteria outside our way of thinking is nonsensical. On the other hand, it does not mean that anything is possible - our work should go in the direction of searching for and exploring of the diverse ways to classify reality.

Best!
Zdenek Skala