Marx didn't regard slavery, feudalism and capitalism as equally
rational means of exploitation, the difference between them lying in
the different objective conditions in which the exploitation takes
place. He explicitly treats them as systems dominated by differing
"passions," the differences both expressing and being expressed by
the internal social relations that define each mode. These relations
are treated as developmentally positive for the dominated class, i.e.
as positively developmental of the human mind. It's this that
explains the substitution of, say, the "passions" of capitalism for
the "passions" of feudalism.
This is also true of different forms of capitalism itself, so an
essential part of the explanation of the particular form of
production relations in differing contexts, e.g. the American south,
Spanish, Portuguese and Dutch colonies, is the particular "passions"
characteristic of domination in each of these contexts, "passions"
that vary depending on the extent to which they retain significant
feudal or early capitalist features. The forms of exploitation are
not simply the instrumentally rational means appropriate in each
context. This is made clear, among other places, in Marx's treatment
of the southern oligarchy in his writing on the American civil war.
The Engels text confirms this in a variety of ways. I've mentioned
its treatment of seafaring. It also does this in its treament of
military capability. Royal power could not defeat the feudal nobility
so long as "armies" consisted of a "mob of serf foot-soldiers" or
"the scum of the towns and escaped serfs."
"To fight the feudal system with a feudal army, in which the soldiers
were bound more closely to their direct suzerains than to the royal
army command, was obviously to move in a vicious circle and not come
off the spot."
This situation was transformed by the development of "a war-worthy
infantry" "in the towns, and among free peasants."
"The basic condition for a war-worthy infantry took shape in the
towns, and among free peasants wherever such were available or had
newly appeared. Until then the knights with their mounted retinue
were not just the kernel, but the army itself; the accompanying mob
of serf foot-soldiers did not count, and appeared to be on hand in
the open field simply for purposes of flight or plunder. As long as
feudalism was in its zenith until the end of the 13th century, it was
the cavalry that fought and decided all battles. But from then on
things change, and, indeed, simultaneously in various places. The
gradual disappearance of serfdom in England created a numerous class
of free peasants, yeomen or tenants, who provided the raw material
for a new infantry conversant in the use of bow and arrow, the
English national weapon of that day."
"Emperor Albrecht's attempt to betray the free (reichsfreie) Swiss
peasants to the Archduke of Austria, that is, himself, gave impetus
to the formation of the first modern infantry of European fame. In
the triumphs of the Swiss over the Austrians, and, notably, over the
Burgundians, armoured knights—mounted or otherwise—suffered a final
setback at the hands of foot-soldiers, the feudal host at the hands
of a budding modern army, knights at the hands of townsmen and free
peasants."
The "virtue" (in the ancient sense of "virtuosity" appropriated by
Hegel in his idea of an "educated" person and in his account, in
terms of this idea, of the positive "educational" effect of
"seafaring") of "townsmen and free peasants" is pointed to and
explained by Marx in his account of "petty mode of production" in
Capital.
"The private property of the laborer in his means of production is
the foundation of petty industry, whether agricultural,
manufacturing, or both; petty industry, again, is an essential
condition for the development of social production and of the free
individuality of the laborer himself. Of course, this petty mode of
production exists also under slavery, serfdom, and other states of
dependence. But it flourishes, it lets loose its whole energy, it
attains its adequate classical form, only where the laborer is the
private owner of his own means of labor set in action by himself: the
peasant of the land which he cultivates, the artisan of the tool
which he handles as a virtuoso."
<http://www.marxists.org/archive/marx/works/1867-c1/ch32.htm#n1>
In an 1864 text contrasting the differential effect on "virtue" in
this sense of wage and slave labour, Marx, invoking Shakespeare,
points as well to a difference between wage-labour in its initial
form and the "independent peasant or craftsman."
"He [the wage-labourer] learns to master himself, in contrast to the
slave, who needs a master. To be sure, this only applies when one
considers the transformation of a serf or slave into a free wage
labourer. The capitalist relation appears here as a step up the
social scale. It is the opposite when an independent peasant or
craftsman is transformed into a wage labourer. What a difference
there is between the proud yeomanry of England, of whom Shakespeare
speaks, and the English agricultural day labourers!"
<http://www.marxists.org/archive/marx/works/1864/economic/ch02a.htm>
The passage on the "petty mode of production" is found in the context
of an account of its destruction by means of "primitive
accumulation," i.e. through 'the stimulus of ['new'] passions the
most infamous, the most sordid, the pettiest, the most meanly odious"
that "spring up in the bosom of society."
"At a certain stage of development, it brings forth the material
agencies for its own dissolution. From that moment new forces and new
passions spring up in the bosom of society; but the old social
organization fetters them and keeps them down. It must be
annihilated; it is annihilated. Its annihilation, the transformation
of the individualized and scattered means of production into socially
concentrated ones, of the pigmy property of the many into the huge
property of the few, the expropriation of the great mass of the
people from the soil, from the means of subsistence, and from the
means of labor, this fearful and painful expropriation of the mass of
the people forms the prelude to the history of capital. It comprises
a series of forcible methods, of which we have passed in review only
those that have been epoch-making as methods of the primitive
accumulation of capital. The expropriation of the immediate producers
was accomplished with merciless Vandalism, and under the stimulus of
passions the most infamous, the most sordid, the pettiest, the most
meanly odious. Self-earned private property, that is based, so to
say, on the fusing together of the isolated, independent laboring-
individual with the conditions of his labor, is supplanted by
capitalistic private property, which rests on exploitation of the
nominally free labor of others, i.e., on wage-labor."
http://www.marxists.org/archive/marx/works/1867-c1/ch32.htm#n1
So the methods of "primitive accumulation" aren't portrayed by Marx
as simply a set of rational methods appropriate to accumulation in a
particular context and to which reversion will recur whenever that
context recurs.
Ted