"By concentrating on what is good in people, by appealing to their idealism and their sense of justice, and by asking them to put their faith in the future, socialists put themselves at a severe disadvantage"

In this quote, Ian McEwan is providing a review of the socialist ideology by highlighting what he perceives as its fundamental vulnerabilities. McEwan recommends that the socialist concentrate on the favorable elements of human nature-- such as idealism and a sense of justice-- may leave socialists at a disadvantage, especially in the practical and often severe realities of political and social life.

The very first part of the quote, "By concentrating on what is great in people," points towards an optimistic view of humanity that socialism espouses. Historically, socialist ideologies have rested on the belief that individuals are naturally cooperative, altruistic, and efficient in working collectively towards the typical good. Socialists frequently stress equitable distribution of resources and chances, stemming from an assumption that people can and will accept policies and actions that prioritize collective well-being over private gain.

The quote then continues, "by appealing to their idealism and their sense of justice," which underscores a reliance on psychological and ethical concepts. Idealism is identified by a pursuit of honorable, sometimes unattainable goals, while a sense of justice involves a deep issue for fairness and equality. Socialism often looks for to mobilize people by aligning with these values, wanting to inspire modification through a vision of a fair and just society.

However, McEwan recommends that this dependence puts socialists at a "extreme downside." In practical terms, the world is complex and often driven by self-interest, where power characteristics, financial interests, and human frailties can stymie idealistic pursuits. The attract a better future or to individuals's much better nature can be weakened by real-world challenges, such as corruption, greed, and resistance to change, which do not line up with the fundamental presumptions of fundamental goodwill and fairness.

Furthermore, McEwan's quote highlights a possible tactical weakness: that by focusing so deeply on suitables and a confident vision of the future, socialists may not properly address the immediate, practical demands of political engagement. In doing so, they might undervalue the opposition or the trouble of enacting systemic change, rendering them less effective in the real-world political arena.

In summary, McEwan's reflection can be viewed as a cautionary note on the limitations of relying exclusively on positive human attributes and future goals without effectively representing the complexities and difficulties present in societal and political structures.