The probe of industrial capitalism is that it gears up two contrasting flows.
The one flow wants to make profit, and needs to squeeze labour to do so Costs must come down, for profit goes up.
The other flow is that of machines. the machine is the principle which allows one to re place the skill of a task with a machine. Each machine therefore as such embodies a rationalized human task. Knitting is therefore broken down into mechanical actions and those actions are then articulated one against another, and made into a mass production process. The affairs of the home and the workshop becomes then affairs of science.
To build a machine is thereofore to convert a human actions into externalized physical reality. it is therefore to drag human action from biology into chemistry and physics.
What s then created is not however Marx insists a simple reduction. True the tasks are broken down, and understood, and yet the tasks remain the same. At the centre of a machine are then the knitting needles or whatever there has always been. It is merely that these needles have been taken out of their human context and made to dance on the wider skies of energy, force and time. The move is therefore not simply reductive. It is rather a means in which small tasks are objectified and then spun across the world as a thing apart. They in a machine have their own life.
Likewise a machine is never a series of bits cobbled together anyhow. On the contrary they are always at every point a continuity. Machines might then nest inside other machines, or might expand into other mechanisms or be caught up in a variety of uses. They might then change what they are, and what they are used for. But in each of these changes the entire point of the machine lies in its homogeneity internally and with other machines. It is therefore always a part of a process greater than it.
Machines therefore not only objectify individual actions, they replace the unity in with those actions; it is not humanity which surround them with their life and their local skill, it is rather then , branch of the wider machine which tasks up a task and orchestrates it against a wider world.
Between then two elements, Capital and machine the gearing up of capitalism lies. Capitalism is the defined within the interaction of these elements; their taking up on one within and through the other. The logic of capitalism is therefore to divide and redivide the human what a human is, and what they can do is being challenged: and Marx, always tuned to historical change knows and welcomes that fact.
What capitalism will do (and how it will undermine itself) is therefore hidden. All we really know is Marx thinks it will happen across the axis of the machines. The unfetterd machine ought, logically enough challenge our very definition of ourselves as separate distinct things. It ought then to open us to another means of living: A means in which our actions cease to be simply our own, but ratherr are taken for what they are, a part in the cog of a wider society. A society which who knows might end up being truly communist.
The process has of course taken far longer than Marx thought: but maybe this is because humanity is more complex? That is it has more level to loose or to objectify in the machine that Marx allowed for. The human then re-asserts itself in these remenants. Alternatively of course it might be the case that humanity is not an idea which dies this way. It strives then become mechanicalized or better recreates itself and its desire to own everything elsewhere, in which case Marx would never be right and Communism would not happen here: or else would happen, but elsewhere humanity would still insist in its power to own (but do it elsewhere). That is the human would change were it was felt. Mechanism would become collective (a multi national, or a state might be such a machine, the global community, are all such communisms),a and yet elsewhere the individual would still insist on its right to be and so bugger up everything if that included the right to conjure itself over political language, belief and so powers.