On Oct 24, 2:58*pm, "Androcles"
wrote:
What's the former principle?
(...)
If you want present an argument for debate, Pentcho, present all
the information. I can't "put to close scrutiny" something as vague
as "former principle".

The "former principle" is given earlier in Clausius' text:

http://www.mdpi.org/lin/clausius/clausius.htm
"To this it must be added that other facts have lately become known
which support the view, that heat is not a substance, but consists in
a motion of the least parts of bodies. If this view is correct, it is
admissible to apply to heat the general mechanical principle that a
motion may be transformed into work, and in such a manner that the
loss of kinetic energy is proportional to the work accomplished. These
facts, with which Carnot also was well acquainted and the importance
of which he has expressly recognized, almost compel us to accept the
equivalence between heat and work, on the modified hypothesis that the
accomplishment of work requires not merely a change in the
distribution of heat, but also an actual consumption of heat, and
that, conversely, heat can be developed again by the expenditure of
work."

Pentcho Valev