Crisis of the modern world by rene Guenon analyzes what guenon thinks are the causes for the decline of civilization in a rigorous and logical way.
He covers history being a repeating cycle of civilizations growing and declining. He explains that cycle as largely caused by the tendency of western man to generate new cultural information, as more information is generated it necessarily separates man from the information which was present at his creation. This is how man becomes separate from the fundamental principles of his existence, causing society to decline.
One of his most important points is his distinction between action and contemplation and claim that contemplation is superior because it connects people to their fundamental principles. Contemplation is participation in the unchanging, the traditional, the lindy. Meanwhile action is often just progress for the sake of progress, which necessarily takes time away from contemplation and produces little of social value on its own.
He also offers a unique critique of democracy from the perspective that is it an unnecessarily quantitative process. Democracy is quantitative because it attributes moral superiority to the voting majority, majority being a quantity. This tendency towards quantity is opposed to qualitative systems such as traditional monarchy or theocracy, which attribute moral divinity to the ruling entity because that entity is simply superior to humanity in a hierarchy.
Guenon has built a very useful dichotomy between quantity and quality, which is incredibly effective at diagnosing much of the problems in society. It explains the excessive societal biases towards materialism, towards quantifiable sciences over religion, towards what can be seen over what can be thought, towards the individual over the common good.
He also provides a unique indirect take on imperialism, indicating that it was once a beneficial process but was ruined by the paradoxical nature of western equality, which can't be satisfied until every country practices as much equality as the west does, necessating the imperialistic spread of this ideology to negate global inequality. Guenon then offers a good critique of egalitarianism, it is obsessed with accessibility and is opposed to elitism. Everyone must be able to participate in everything at the same level. This causes the quality of existing knowledge and cultural information to drop until it is comprehensible by the general population. Once again quality is losing ground to a quantity, this quantity being the number of people capable of participating.
Overall this book's analysis is incredibly unique, you won't find ideas like this outside of Guenon. It is prophetic, its predictions are all coming true in today's world, making his ideas even more insightful today than when they were first written. I recommend it to anyone interested in understanding the specific mechanisms behind the decline of the western world. I would also recommend his later book "The Reign of Quantity and the Signs of the Times", which expands on this book greatly.
I take significant inspiration from Guenon in this article.