Heraclitus and constant change - a vexed question
THE thought of Heraclitus of Ephesus is still often summarized
as " All things are flowing ", panta rhei; by which it is inferred
that everything is in constant change. This summary goes back
ultimately to Plato, who at Cratylus, 402a, wrote as follows:
" Heraclitus says somewhere that everything is moving and
nothing stays still, and likening things to the flow of a river he
says that you could not step twice into the same river ". Plato's
interpretation was adopted by Aristotle, and through him
by Theophrastus, whose " Opinions of the Physicists " became the
basis of all later ancient accounts. Recently, however, some
scholars have become sceptical about the accuracy of the Platonic-
Aristotelian interpretation of Heraclitus' views on change;
and with good cause, for the fact is that there is nothing in the
extant fragments about the constant flux of all things, even
though one would have expected the survival of some original
support for a view so widely popularized in the fourth century.
The assumption from this is that the constancy of change is not
an idea which Heraclitus particularly stressed. What he undoubtedly did stress above all else was his discovery of the unity
that subsists in apparent opposites: it is with failure to apprehend this unity, that he so bitterly reproaches his fellow men. (G.s. Kirk, 'Natural Change in Heraclitus', Mind, Vol. 60, No. 237 (Jan., 1951), pp. 35-42: 35.)
Heraclitus does of course recognise the ubiquity of change but this does not mean that he thinks everything is changing all the time. Rather, and not at all the same thing, the realises 'the inevitability of
change, sooner or later, in every division of nature'. (Kirk: 38.)
But what of Diels, Fragment 12: 'Upon those who step into the same rivers, different and different waters flow' ? It is a stretch to derive from this that Heraclitus regards things - all things in the cosmos (leaving aside for a moment the logos) - as constantly changing like the water a river.
Without the assumption of constant change in the cosmos, your contrast between such change and 'at least one permanent, unique, eternal thing that transcends the cosmos', namely the logos, is problematic. One side of the contrast - constant change - falls away.
The nature of the logos still needs attention, though; and this is the next task.
The logos is best approached through Heraclitus's idea of 'measure' (metron).
In fr. 30
the cosmos is an everliving fire, kindling in measures and going
out in measures (aptomenon metra kai aposbenunmenon metra).
In fr. 31 the sea is measured (metreetai) into the same proportion
as applied to it before it became earth. In fr. 90 fire is an exchange
for all things and all things for fire as goods for gold and gold for
goods. In fr. 88 (of a group of opposites like summer-winter)
" these things change places and are those, and those change
places again and are these ", where metapesonta implies a regular
exchange. In fr. 94 " the sun will not overstep his measures
(metra); if he does, the Erinyes, agents of Dike [justice], will find him
out " In fr. 51 that which tends apart also coincides: it is a
palintonos harmonie, a join which works in both directions like the
string of a bow or a lyre; note that here too the tension must operate equally in each direction - the inward pull of the string
must equal the outward pull of the arms of the instrument,
otherwise the string is too loose or the whole instrument breaks.
Akin to the idea of measure is that of plan and direction in the
world, as in fr. 41: wisdom is to know how all things are guided;
and in fr. 80: all things happen by strife and necessity. The concept of Logos supplements this whole picture; Logos for
Heraclitus is the single formula or plan according to which all
things happen... (Kirk: 37-8.)
As such, the logos is immanent in the cosmos, not transcendent of it; it guides or (as I think contrary to your suggestion) it informs - is 'inside* - the cosmos as its inherent principle. Heraclitus probably does see it as 'permanent, unique, eternal'.
Note on the cosmos'
You seem to regard the cosmos as a 'world' - 'For me, whether the world is portrayed as mobile or immobile is only a question of referential.' A word of caution :
the use of kosmos - 'cosmos' - in fr. 30: " This kosmos no man or
god made; it was, is, and shall be ". Now 'kosmos* for Heraclitus,
in the early fifth century, must still have retained much of its
basic meaning of "order", "regularity"; it cannot just mean
" world " in our practical sense, and is perhaps best translated
as "organism". (Kirk: 38.)