It is well-known that Marx never provided a detailed account of the basic structure of the future communist society that he predicted.("Democracy" here connoting individual and collective self-determination, rather than political forms of governance.) The basic argument runs: that it is undemocratic to limit the self-determination of individuals; that providing a plan or blueprint for a socialist society limits the self-determination of individuals; and that therefore the provision of plans and blueprints for a socialist society is undemocratic. If we add in the assumption that undemocratic means are undesirable; then we can conclude that it is undesirable to provide plans or blueprints of a future socialist society. One central reason for resisting this argument is that it is hard to identify a plausible account of the conditions for self-determination, according to which it is necessarily true that merely providing a socialist plan or blueprint restricts self-determination. Indeed, one might heretically think that detailed plans and blueprints often tend to promote self-determination, helping individuals think about where it is they want to go, and how they want to get there. Marx's second argument rests on an epistemological claim that that utopian plans and blueprints are impossible, because they require accurate knowledge of the future of a kind which cannot be had. The basic argument starts from the assumption that to be of any use a blueprint must facilitate the construction of a future socialist society. Moreover, to facilitate the construction of a future socialist society a blueprint must be completely accurate; and to be completely accurate a blueprint must predict all the relevant circumstances of that future society. However, since it is not possible--given the complexity of the social world and the limitations of human nature--to predict all the relevant circumstances of that future society, we can conclude that socialist blueprints are of no use. One central reason for resisting this argument is that, whilst it is hard to deny that completely accurate plans are impossible (given the complexity of the world and the limitations of human understanding), the claim that only completely accurate plans are useful seems doubtful. Plans are not simply predictions, and providing less than wholly accurate plans for ourselves often forms part of the process whereby we help determine the future for ourselves (insofar as that is possible). Marx's third argument depends on an empirical claim that utopian plans and blueprints are unnecessary, because satisfactory solutions to social problems emerge automatically from the unfolding of the historical process without themselves needing to be designed. The basic argument runs as follows: that utopian blueprints describe the basic structure of the socialist society of the future; and that such blueprints are necessary if and only if the basic structure of future socialist society needs to be designed. However, given that the basic structure of the future socialist society develops automatically (without design assistance) within capitalist society; and that the role of human agency in this unfolding historical process is to deliver (not design) that basic structure, Marx concludes that utopian blueprints are redundant. Reasons for resisting this argument include scepticism about both Marx's reasoning and the empirical record. Marx is certain that humankind does not need to design the basic structure of the future socialist society, but it is not really made clear who or what does that designing in its place. Moreover, the path of historical development since Marx's day does not obviously confirm the complex empirical claim that the basic structure of socialist society is developing automatically within existing capitalism, needing only to be delivered (and not designed) by human agency. This brief discussion suggests that there are cogent grounds for doubting Marx's claim that utopian plans and blueprints are necessarily undemocratic, impossible, and redundant. Finally, recall that Marx is less enthusiastic about the second and subsequent generations of utopians, than he is about the original triumvirate. We might reasonably wonder about the rationale for greater criticism of later utopians. It is important to recognise that it is not that second and subsequent generations make more or grosser errors than the original triumvirate. (Indeed, Marx appears to think that all these different generations largely held the same views, and made the same mistakes). The relevant difference is rather that, by comparison with their successors, this first generation were not to blame for those errors. In short, the rationale behind Marx's preference for the first over the second and subsequent generations of utopian socialists is based on an understanding of historical development and an associated notion of culpability. Marx held that the intellectual formation of this first generation took place in a historical context (the cusp of the eighteenth and nineteenth centuries) which was sufficiently developed to provoke socialist criticism, but not sufficiently developed for that socialist criticism to escape serious misunderstandings (Cohen 2000: 51). Since neither the material conditions of modern society, nor the historical agent capable of bringing socialism about, were sufficiently developed, this first generation were bound to develop faulty accounts of the nature of, and transition to, socialism. However, that defence--the historical unavoidability of error--is not available to subsequent generations who, despite significantly changed circumstances, hold fast to the original views of their intellectual forerunners. Marx maintains that more recent utopians, unlike the original triumvirate, really ought to know better. 9. Marx's Legacy At this point, we might be expected briefly to survey Marx's legacy. That legacy is often elaborated in terms of movements and thinkers. However, so understood, the controversy and scale of that legacy make brevity impossible, and this entry is already long enough. All we can do here is gesture at the history and mention some further reading. The chronology here might provisionally be divided into three historical periods: from Marx's death until the Russia Revolution (1917); from the Russian Revolution to the fall of the Berlin Wall (1989); and since 1989. It seems hard to say much that is certain about the last of these periods, but some generalisations about the first two might be hazarded. That first period of "Classical Marxism" can be thought of in two generational waves.For instance, in the Communist Manifesto, he complains that utopian socialists hold a mistaken "ahistorical" view of social change. The utopians purportedly fail to understand that the achievement of socialism depends on conditions which can only emerge at a certain stage of historical development. They might, for instance, recognise that there are strategic preconditions for socialism (for instance, the right blueprint and sufficient will to put it into practice), but (mistakenly on Marx's account) imagine that those preconditions could have appeared at any point in time. This complaint is non-foundational in that one can accept that there are historical conditions for establishing a socialist society, and that the utopian socialists fail to understand this, without thereby having a reason to abandon utopianism as such. A commitment to the necessity and desirability of socialist design does not require one to hold an "ahistorical" view of social change.Instead, the focus is on the three main foundational arguments against utopianism that can be located in Marx's writings; namely, that utopian plans and blueprints are necessarily undemocratic, impossible, and redundant (see Leopold 2016).