Yes, indeed, and this is a very hopeful trend. But cities are not a "natural state" from which humans have departed and to which we can "return". They are the very definition of artificial.
What do you think artificial means? Here, I'll help you:
"made or produced by human beings rather than occurring naturally"
Artificial may be considered a proper subset of "natural", but what humans do is different enough from what the rest of nature does that it's useful to distinguish between those things that exist because we humans put our effort into making them exist and those things that exist without our help. Cities are in the former category.
This sounds like splitting hairs over semantics because applying that definition of artificial in this context is circular: all things humans do are artificial because artificial is defined as things humans do.
Humans gather at residential centers with populations in the millions, yeah, so do ants. Are we going to call that antificial?
The underlying point is that human beings have natural proclivities toward certain positive/healthy/beneficial behaviors, regardless of whether or not those behaviors occur spontaneously. This principle probably pervades nature beyond humanity, but Tolstoy's point is that only humans recognize this, and some deliberately place themselves in opposition.
Not matter what we call the words, I believe Tolstoy (and Ganhi, and Jesus, and the people replying to this post) are correct: the only way to succeed as civilization, whether it means ending violence or even just eliminating wealth gaps, is to recognize and develop love for one another.
Seriously? You cannot discern the qualitative differences between human social interactions and ant social interactions?
Gathering in groups is natural. Doing it in residential centers full of buildings that have right angles in their construction and flush toilets and electrical outlets and internet connections is artificial.
> the only way to succeed as civilization, whether it means ending violence or even just eliminating wealth gaps, is to recognize and develop love for one another
Love? How about just respect?
But it doesn't matter what label you attach to it. I agree that the only way to achieve peace is to reach some state of mind, and I don't particularly care whether you call it "love" or "respect" or "nirvana" or the flying spaghetti monster. I don't want to quibble over terminology. What matters is that this state is not the natural order of things. Mankind has never been in this state, and so we cannot "return" to this state. What we have been doing is steadily making progress towards this state. But we have made this progress by mastering the laws of physics, not by denying them.