Reconstruction and Revolution both assert that the problems resulting from capitalism are structural problems--they are problems with the system itself. Reconstruction and revolution both advocate systemic change, as opposed to mere tinkering. Their vision of the good society, the end of their labors (if there ever is such a end), entails a fundamentally different system.
Now, although Reconstruction and Revolution both agree to a fair extent in their critique, they differ in their strategy. Reconstruction asserts that the new system can be built within the old, that we can build the framework of the future system today through social experimentation and innovation and gradually scale it up to replace the old system. Gar Alperovitz has notably written on such "evolutionary reconstruction." It is also similar to the approaches advocated a century ago by the likes of Felix Adler and John Dewey. Reconstruction believes in remodeling old institutions in light of new values and creating new institutions that better reflect such changed values.
Revolution, however, asserts that the old system must be scrapped in full before the new system can be built. Revolution insists that we must destroy first and build second. It acknowledges that we might know what we want to build, but the first task is to get the system to collapse from its own contradictions---or provoke its collapse even sooner. Revolution believes that existing institutions cannot be transformed through new values and new, more democratic designs--they must be replaced.
Reform, unlike Reconstruction and Revolution, does not seek systemic change. Because of this, Reform often suffers from inherent limitations in argument. Reform sells its measures for greater equity on the grounds of "increased productivity" or "economic growth." Reform feels more comfortable speaking in terms of efficiency or even utility than in terms of justice or rights. Reform will push forward until it hits the wall of profit, and then it will stop. It will push no further. Reform is content with regulation to keep the "excesses" of capitalism in check, but it does not seek redesign.
I recently recalled a passage from Felix Adler's The Reconstruction of the Spiritual Ideal (1923) on such limits of liberal reformist opportunism:
Sentiment, self-interest, can be appealed to, and the factors that make for unfairness can be made to yield to a certain extent. Wages can be raised so long as their increase is consistent with the accumulation of profit. When, however, the cessation of profit itself is threatened, there is an end of concession. The motive, the principle that operates in the competitive system then stands forth as an insurmountable obstacle. Better housing can be supplied here and there by benevolent employers--a complete change in the housing system is resisted tooth and nail. Certain forms of the piratical instinct in business are prohibited; big business declares with self-complacency, we have seen a new light; but the same ruthless instinct, like a flood which is dyked at one point, breaks out in new quarters, under new modes or disguises. There is no help for it. Man is actuated by motives, and unless the motives can be changed, there will be no steadfast, no large, lasting improvement, even in material conditions. …. There will be a little lightening of their heavy burden, the scanty requirements of what is called a “decent” way of living may be provided, so far as is compatible with the continued living in palaces of the rich; but social reconstruction in any thorouhgoing sense will not take place (pp. 128-9).
Reform, thus, suffers from its inherent shortness of vision and ambition.