I agree with Michael Perelman about the importance of a
historical approach, so long as one views it reflexively.
The simpler economic categories like commodity and money
do preceed capital historically, and this is necessarily so
or one could not theorise how capital came into existence.
However, in reflecting upon the categories of a more advanced
society one gains an understanding of the real significance
of the historically and logically anterior categories.
Thus as several people have emphasised, the concept of
abstract labour presupposes generalised commodity production,
but after that we can apply it to understand the historically
earlier simpler forms of commodity production.
But this cuts two ways. Just as the categories of commodity
production are best understood once wage labour exists, the
structure of value relations as a process of social reproduction
are best understood from the standpoint of socialist society.
The conceptual apparattus that we now use to analyse capitalist
economies - including i/o tables - could not have been thought
of without the socialist revolutions of this century.