That phrase could mean anything in practice that anyone wants it to mean. If we're going to discuss these things, we should be specific. What specific policy is desired, and how is it going to help? "Humanity" and "democracy" are not economic policies, nor are they specific enough goals to design policies around.
I am unsure whether economic equality is a goal that we should strive toward. I wonder if a better measure for our economy would be how well off people are at each place in the distribution. Almost all middle class people in America today still have really nice TVs, mobile phones, Internet, etc., which suggests that their standard of living is quite good in absolute terms. We should be looking at absolute terms, not relative terms.
Taxing the wealthy has undesirable effects. It's not as if wealthy people take their money and put it under their mattress. No, they invest it. That investment money flows to other corporations who then spend it on goods and services, or spend it on their employees. All of the wealth that the rich accumulate makes its way back into the economy, except it's at the direction of the rich according to their investment decisions. The alternative, if you tax the rich, is that the same money flows to the government and the government spends it on programs.
That's certainly valuable, and I believe it makes sense for the government to have tax revenue to spend on its programs, but I don't necessarily think that more revenue for more programs will lead to better results. I'd rather that we spend substantially less on wars, for example, and redirect that money into infrastructure for our own country.
Take the F-35 development program - the government has basically thrown over a trillion dollars down the drain (I'm being hyperbolic, but it's really pretty bad). A trillion dollars!! The government would have plenty of tax revenue to spend on smart infrastructure investments if it stopped throwing money away on programs like that.
I'd hazard a guess that wealthy investors through their investments are more effective at creating wealth and raising the standard of living in the country than the government is (on a marginal basis from where we are today). Investors are far better at examining where their money goes, what effect it has, and doubling down on investments that demonstrate promising results, and pulling the plug on pointless ones. The government by comparison keeps burning more and more money on programs that are clearly ineffective - examine the Healthcare.gov or F-35 boondoggles. Private investors do better. Let them keep their money to invest it smartly.