12 Rules for Life: An Antidote for Chaos

Twelve Rules for life presents a number of "rules" to help live a better life. The rules have a classical twist to them. He uses biblical and literary stories to help illustrate his points. There was a seeming contradiction as he tends to favor the benefits of "traditions" in society as opposed to "newer ideas." (For example coddling to various smaller and smaller interest groups in the name of diversity is seen as a negative compared to a more unifying society.) However, he also favors our society as it is much less violent than other "older" societies such as hunter gatherers or even ancient Rome. Perhaps this contradiction is justified in an oscillation. We may be on a long term path to a better society. However, to get there, there may be a number of steps that spin us radically in the wrong direction before we continue on the upward path.
Early sections focus on taking responsibility for self. People are notorious for not taking their medication. Even after waiting a long time for an organ transplant, recipients will often not take anti-rejection meds. However, they tend to be very certain to give their dogs their medication. It is important to care for yourself. Even altruistically, if you don't care for yourself, you are not able to care for others as well. People that are week are likely to get bullied and further act in ways that induce further bullying. Merely rising up to good posture can help improve things.
Children must also be disciplined appropriately. We can often be lazy and let our children run over us. This hurts us in the short term (including limiting the social activities that parents can do.) It also hurts the children in the long term. They get behind in their socialization and don't have friends and continue on a negative spiral.
We must not get caught up in attempting to change the world when our own self is in need of change. He identifies the "hidden motives" in many change agents. Marxism sought to embolden the working class. However, it was primarily the intellectuals that used it as a means of fight against the ruling elite. We see that constantly in many of our policies that are carried out "for the benefit of others", such as bus systems that attempt to reduce congestion by getting "other people" to ride the buses.
The author also laments the act of "blaming white males" for many of society's ills. Many roles in society have evolved out of genetic strengths of either sex. Equity of opportunity is fine. However, people will tend to congregate in areas that they can succeed in. Trying to shame groups or force others into roles they do not like only serves to harm society and does not help things. Girls are typically more comfortable doing "boy things" than boys are doing "girl things". As more feminine behaviors come to dominate, that leaves boys out in the cold. (This can in part explain the rise of political figures like trump.)
In providing his "12 rules", Peterson provides a fairly thorough critique of the "accepted" academic political correct beliefs of today. The thesis can be summed up with a few maxims: You can only control yourself. Do the best to do that with what we have learned through history. Long standing cultural norms are there because they work. We can make improvements to them, but don't through them out. Don be the victim. Be what you want to be.