Here's a go at defining socialism. It's presented as a spectrum of increasing government responsibility.
Anarchy: no shared government or rules, everyone seeks their own advantage and guards against the depredations of others. Private ownership exists so far as people can keep control of things. Tribal coalitions usually form. Human potential is not developed.
Libertarian Capitalism: private ownership of the means of production, government involvement limited to defense of the nation, and prevention of crimes against person and property. This may include regulations preventing eg very unsafe work practices, dumping toxic waste, etc. It may include critical infrastructure. Specifically, the welfare of individual people in terms of housing, education and health care are
not the responsibility of the government.
Socialism: private ownership of the means of production, government involvement includes defense, prevention of crimes against person or property and also includes provision for "the public good", which may include, depending on the strength of the socialism:
(a) infrastructure like roads, sewerage, water, storm drainage etc;
(b) human services like universal education, universal health care, unemployment/poverty relief
(c) economic management such as Keynesian interventions and bailouts
(d) government ownership of utilities like rail, power, etc
(e) etc etc...
Communism: Government control of the means of production and government responsibility for almost all aspects of people's welfare.
Which things are/should be government responsibilities is the core of the debate.
It is often argued that the social provisions that benefit the poor directly (especially education) indirectly benefit the wealthy (eg by creating a well-prepared workforce, thus enabling the economic activity that the wealthy get wealthy from). Likewise, were it not for social security, huge numbers of people would be so desperately poor as to constitute a dangerous menace to the advanced society we have. These are just examples.
Where the line should be drawn is a matter of ongoing debate.
The philosopher John Rawls offers the following general answer. What is "fair" is what rational beings would agree to from the "original position" which is behind the "veil of ignorance". To be in the original position, imagine that you know all the significant facts about your society (say, 1% wealthy plutocrats, 20% upper middle class, 40% working middle class, 20% working poor, 19% very poor) but that you
do not know which group you are in. Since you don't know which group you're in, it would be irrational to agree to a law that grossly favors one group over the other.
It is often argued that it is rational to "hedge your bets" in favour of more socialism rather than less. Firstly, you're very unlikely to be one of the very rich, and secondly even if you are very rich, and are paying heavy taxes to support your fellow citizens' health and education, well shucks, you're still very rich. And what well educated employees you can get!
The counter argument is that over burdening the rich will reduce economic growth, cost jobs, cut wages and thus harm the welfare of the working and middle classes. So it is rational to allow wealthy individuals and businesses more freedom to do business, because in the long run the increasing prosperity will benefit everyone more than immediate social support.
Which of these arguments is correct is left as an exercise for the class.
