Money, from a philosophical standpoint, is a measure of how much good people have done for others, in our economy.
When I go to work, I’m not making things for myself. I’m making things for other people, things that help them, heal them, make them happy, or feel more secure. Likewise, all of those people are doing the same thing. Every day, they go in to work and make things to help everyone else.
If you pictured us as a small village, money is like good will. If I’m the guy in town who knows how to fix appliances, I would go around fixing everyone’s appliances, and because it’s a small town, everyone would be happy with me. When I needed a cake baked, the cake baker - whose washing machine I fixed - would happily bake me a cake. If I needed a need pair of pants, the tailor would make me some pants.
But, at the point where I ask the mechanic to build me a car - from scratch - the total work of which would take thousands of hours for a lone man to accomplish, the fact that I fixed his lawn mower a few years back really doesn’t cut it. If I were the mechanic, I’d save that sort of work for the doctor, who saved my kid from imminent death or something, not just any other person who’s done a few helpful things for me. After all, for the whole time that the mechanic is making the one car, he’ll have to ignore and not help out anyone else in town. That’s not good for the town and who is going to give the mechanic food for all that time? It’s not reasonable for people to support the mechanic, while he makes a car for one guy.
In that sort of world, where people keep track of how much good will they personally have with someone, it’s impossible for big things to get done. If I really wanted a car, for whatever reason, I’d have to gather everyone in town and do a deal where I say, “I’ll fix appliances for all of you, for the rest of time, asking nothing in return, if you treat the mechanic like he was me and give him pants and cakes and stuff, as though he had done the work for you that I had done.” That’s rather unwieldy.
Money allows you to accomplish that, without having to get everyone together and hammer out details. If I do small jobs for a thousand people, I can get a thousand small rewards. Though each reward may be small, when added up, it might equal a lot. So then I can take that large wad o’ cash to the mechanic, he’ll gladly take it. He can work on my car while trading the work I did with others, without their having to know where he got that money from. They can assume that he did an equivalent or greater favor for someone and thus they’re willing to do a favor for him.
As said, money is just a measure of how much good will you’ve done in your life. And, since everything one possesses (these days) is bought for money, your personal possessions are also a measure of how much good you have done in your life.
So now if you do no good in your life, and instead just steal things from people, then in what way is that good? Good is, by definition, doing things for others. Not doing things for others and then demanding or taking things from them is, by definition, bad.
When people buy things, they’re trading that money against everything else they could have used it for. If I buy a painting, I’m not buying food. I need food to not die, so I have to buy food. That’s always priority one. So to get that painting, I have to have chosen that it was worth it to me to get out there and do the extra work so that I can justify doing something that’s dangerous to my survival, when I trade away my money for something that I can’t eat. But I might do it because that’s just what it takes for me to be happy and satisfied in life. Maybe I just can’t abide by the idea of living a life with nothing beautiful to look at.
Now, if you take that painting, you’re removing something that I traded my survival for. You’re removing something that I wanted for my own mental health and life satisfaction. Sure, maybe you don’t think that a painting is worthwhile, or that it’s worth working hard so that you can buy a Porsche, but we’re not all the same person. What has value to you and what has value to me aren’t the same thing. You have to trust that, if I forked out money for something, it’s something that has value to me. And if you take that from me, you’re lowering the quality of my life.
By thieving, not only are you doing no good for the world, you’re (however small or large it might be) actively hurting others.