Human nature is that the male of the species seeks to acquire territory, both physical and metaphysical, in order to demonstrate his superior genes to the female. Capitalism is the "civilized" method of acquiring such territory, without resort to violent physical force as a means of achieving the acquisition. Socialism is a contrary force that helps maintain the lesser genetically qualified population (i.e., the workers) from being reduced to being the absolute slaves of the capitalists. Socialism also helps prevent the violent revolution of the working class. Money (which is the modern mechanism used to efficiently exchange territory) is like a magnet -- it sticks to other money. The more you have the more easily it is acquired. The 1930s depression is a testament to the fact that if you allow pure market forces to operate freely, and restrict the money supply from increasing per capita with the population increase, that eventually all of the money will flow into the hands of those at the top, and nothing will be left for the rest -- and the consequence is, economic collapse. A pure capitalist system will cycle to extremes, which means poverty and violent revolution. A pure socialist system will prevent any economic cycle by removing the availability of profit for some at the expense of others, and this prevents the alpha males from achieving the superiority necessary to obtaining the genetically superior females. The consequence of this is also, revolution. The conclusion, however, suggested by the poster's original question, i.e., that capitalism needs to promote socialism is also specious. Neither system needs the other. Promoting both systems is likely to smooth out the cycle of the rise and fall of civilization, but assuming that this cycle is a reasonably random operation of nature, then eventually, no matter how we may attempt to mitigate it, there will be a large swing to the downside, and civilization will collapse -- just as it has always done in the past.
It would be more accurate to say capitalism is a civilized "justification" for maintaining ownership of property obtained, often, through various non-capitalistic means. Bottom line, capitalism is non-existent with socialism because money itself is a socialist concept.
Both systems need to coexist, but one system becomes more fashionable based on how new generations are led to believe. Today, Socialism is the rage (a lot of anti-Americanism is really hostility toward Capitalism) Capitalism works well when poor people want little and feel hopeful. Mix it with some good Socialism, and you can sustain it. When the balance is lost, Socialism begins to take over like rust, as more people are taught/enabled to want/expect more while feeling more hopeless. So rather than compelling individuals to improve themselves, society degenerates into a form of idealized Socialism, collectivism, and altruism, in the form of succumbing to intolerant religions and believing that taking from the rich will solve all of their problems.
How about this ........ "..... Now try to think out of the box by taking into account Human Nature and show why and how Socialism needs to promote Capitalism and profit from it with the power of Money." I would much rather write about that.
Here's thinking outside the box, I think so anyway. When private entities become too powerful and monopolistic relative to the power that public/government entities have, these monopolistic entities effectively become a government of sorts, because they have powers over both the individual and the state normally associated only with government, and they inherit all the waste and inefficiency normally associated with government bureaucracy. Capitalism needs a government that is kept strong and somewhat socialist in order to have the power to regulate or break up monopolies, trusts, and even labor unions (which are monopolies on labor), in order to artificially maintain competition and enjoy the efficiency that competition brings.
If you think about it, neither the capitalism we believe we practice in the States is really capitalism, nor the socialism practiced in Europe is really socialism (but closer to it than our capitalism is). A truly capitalistic society would devolve into anarcho-libertarianism, which would quickly go into further anarchy and end up much like what we have in the middle east these days. A truly socialistic society becomes a failed despotic totalitarian state. Been there, done that. Capitalistic forces are increasing in the US. This might have the unintended consequence of causing great disruption for the unwashed masses as they find themselves unable to cope or adapt to a world of increasing competition, and relatively less middle ground. The new rich will be richer, but there will be fewer of them, and more of us will be depending on them. One major problem that I have is, when an extremely small number of elites control the bulk of the income, what will happen to the populous who can't serve them or profit off of those who do? And if I was one of those elites, I would be pretty worried about stepping out of my ivory towers - 100,000:1 ain't good odds, even with a security force. Science-fictiony, I know, but is it all that implausible? Oscillation between capitalism and socialism creates volatility, which as we all know permits profit. The population has good years and bad years, smart money makes its money during the good years and hunkers down in the bad. The populous stays calm, and enjoys intermittent prosperity while having a safety net to protect it. Don't forget why those safety nets exist - for the protection of the elites! Its the whole "NIMBY" thing. Pure socialism makes you soft. Pure capitalism without social safety nets breeds revolution. On the spectrum of economic philosophies, they lie closer to each other than you think, and we go between the two as the prevailing political and social winds blow. Did I answer the question? See my other (ignored) post.