What did Luxemburg mean by this statement? And what does this have to do with the day-to-day organizing done by activists at the local level, today?

Luxemburg noticed that these two elements – the "mass character" of the radical project and its insistence on the long-rage vision of a post-capitalist "final aim" – tend systematically to come apart. On the one hand, when activists strive to relate to masses of people, there is an understandable tendency to consider "bracketing" or ignoring the more ambitious aims of radicalism, such as overturning capitalism and radically transforming the political process, since these aims are unpopular, and we may fear isolation and irrelevance if we put too much emphasis on them. On the other hand, when we recoil against this kind of adaptation to the limitations of "mainstream politics" there is a reverse, but also understandable tendency to fixate on our rejection of reformism, and to renounce the attempt to win over masses of people, the vast majority of whom are convinced non-radicals, on the grounds that these people are supposedly too corrupted by their immersion in consumer capitalism and too brainwashed by media manipulation to be won over to the cause of anti-capitalist radicalism.

What we see at work here, according to Luxemburg’s account, are two temptations that continually threaten to derail the radical project: the temptation to set aside the project’s "final aim," and the reverse temptation to abandon the project’s "mass character." So persistent and seductive are these temptations that the political Left is continually splitting up into two camps, each of which is equally (but for opposite reasons) incompatible with the radical project. On the one side are the people that radicals like Luxemburg used to call "opportunists," meaning activists who seek to find a shortcut toward social change by watering down their goals and principles ("abandoning the final aim," in Luxemburg’s terms) in order to appeal to a broader section of the populace, perhaps thereby to gain a foothold in the legislature, or at least a voice in mainstream politics. This first group gives up radicalism in exchange for what they regard as "relevance" and the prospect of wider influence. On the other side of this divide are the people that radicals like Luxemburg used to call "sectarians," that is, people who allow themselves to be cut off from the masses of working-class people, and create a world of their own, in which a certain kind of ideological purity and self-righteousness is preserved, but at the cost of having no capacity or even interest in relating politically to the average working-class person.

These two types – perhaps best exemplified by the ex-radical turned social-democratic politician on the one hand, and the "lifestyle anarchist," scornful of the "sheep" who comprise the working class, on the other – pervade the political life of the Left. (This has been so for centuries, and on all continents, as any study of the history of socialist politics will amply demonstrate.) We are all very familiar with these two types, and no doubt we all sometimes slide in one or the other of these two directions to some extent. But what could have led Luxemburg to define the radical project as, quite specifically, the imperative to "negotiate a course between these two reefs"? Why should we think of radicalism, as she did, as the rejection of these two alternatives?

Paradoxically, Luxemburg wants us to avoid these "two reefs," or two mortal dangers, not because they both represent bad impulses, which can only lead us astray, but on the contrary because both impulses are essentially correct, although each is correct in a dangerously one-sided way. We really should insist that our political project, and our political organizing efforts, must be relevant to "where people are at" today, so that we are not just speaking to ourselves, or "preaching to the choir," but are instead systematically reaching out to wider and wider circles of the broader community. And yet, the apparently contrary impulse, to insist on connecting the work we do today with the long-range vision of a fundamental revolutionary transformation of society, is also crucial to our project as radical activists. Otherwise we are not doing radical activism at all, but what Luxemburg calls "bourgeois reformism," or what we would today call "liberalism."

The conclusion that Luxemburg draws from these considerations is quite simple. What makes the political project of radicalism different from both "liberal reformism" and "lifestyle anarchism" is that radicals persist in pursuing a path that these other sorts of activists tend to renounce: the path of seeking radical social change by means of grassroots mass mobilization. This is a path that seeks to connect with masses of people, although not by means of that most domesticated mode of mass participation – electoral politics – which is favored by liberals and social democrats, but instead by means of building grassroots protest movements in which people participate by taking to the streets to fight for social justice. At the same time, though, it is a path that looks beyond the narrow horizons of the "realistic politician," and sets its sights higher than the "reformists" who accept the limits of capitalism. The radical path aims instead to eradicate capitalism altogether, and with it all forms of social and environmental injustice, political and economic oppression.

This project – seeking radical change by means of grassroots mass mobilization – is rejected by the reformist in favor of a fixation on elections and public policy-making, and also by the "lifestyle anarchist" in favor of maintaining a posture of self-righteous pseudo-militancy. Only the radical project tries to bridge the gap between them, to connect "the mass character" of working-class politics with the "final aim" of a post-capitalist revolutionary transformation of society.

Successfully navigating a course between the two reefs of "sectarianism" and "opportunism" is no doubt difficult, because the two pressures that push us toward these dangers are always at work and are often hard to resist. But that is the particular challenge that defines the project of radical activism. And if radicals don’t take this challenge seriously, no one else will.