Nature and Labour

 Max says about the relation of labour and the human nature:

By thus acting on the external world and changing it, he at the same time changes his own nature. He develops his slumbering powers and compels them to act in obedience to his sway. We are not now dealing with those primitive instinctive forms of labour that remind us of the mere animal.

Indem er durch diese Bewegung auf die Natur ausser ihm wirkt und sie verändert, verändert er zugleich seine eigne Natur. Er entwickelt  die in ihr schlummernden Potenzen und unterwirft das Spiel ihrer Kräfte seiner eignen Botmässigkeit. Wir haben es hir nicht mit den ersten tierartig instinktmässigen Formen der Arbeit zu tun. (192)

Mediante ese movimiento obra en la naturaleza externa a él y la altera, y así altera al mismo tiempo su propia naturaleza. Desarrolla las potencias que dormían en ella y somete a su propio dominio el funcionamiento de sus fuerzas. No nos interesan aquí las primeras fomras de trabajo, animalescamente instintivas. (193)

a) It seems like Marx is changing his argument. Instead of using bourgeois categories, here it seems he is using labour as timeless category.
b) However, labour also depends on the historical context, as labour changes nature (and human "inner" nature).
c) There are very different connotations in the word "labour" in Europe. Marx intellectually comes from a Lutheran tradition. The protestant tradition of England often has a more funcionalistic relation to work. And the catholic tradition is far from conceding labour the same moral role as in the german tradition. Think about german words like "Beruf" which links work to an almost divine mission in comparison to the english word "job" used also in the rest of the world to describe work which is done whithout deeper inner relationship to the work.
d) Although Marx, by insisting that work is somehow natural, he argues agains utopians like Fourier who think that work could be pure joy and pleasure, in his (Lutheran) tradition the idea of "joy of work" (Arbeitsfreude) is quite deep rooted. Huge parts of the struggle for un-alienated work can only be understood when supposing that work should and could be joyfull.