This book by Thomas Sowell takes it's place in 3rd position in my all time book hall of fame behind "Closing of the American Mind" and "Ideas Have Consequences". The book is smaller in the scope of ideas dealt with, but much more reachable than than the other two books.
The central theme is that there are two primary visions that people and "schools of thought" have as their initial "pre-analytic models of thinking".
Constrained - Largely the Judaeo / Christian view of man as "flawed, incomplete, incapable of reaching perfection". Social goods must be obtained by providing incentives and disincentives to allow individuals and society in general to move forward. Much of human knowledge is implicit -- buried in traditions, mores, institutions and practices that are effectively unconscious. Trying to make rapid and supposedly "well understood" change due to supposedly superior modern knowledge is likely to destroy rather than improve the situation of most of society.
Unconstrained -- Man is the measure of all things and man's basic character is good and clearly perfectible. Rather than attempting to vaguely move forward via indirect incentives and disincentives, the most intellectually and morally superior people of the current time must take direct action to achieve results. The results desired are clear -- equality of economic OUTCOME, "justice" of all sorts, recognition of each person as a unique, special and worthy individual. Since human kind is moving forward, those alive today are best able to decide what is best -- history, tradition, laws, institutions, cultures, etc are dangerous in that they are always less perfect than the currently most advanced thinking of the current intellectuals.
Naturally, nobody is purely constrained or unconstrained, but in general, conservatives start from the constrained vision and liberals start from the unconstrained. Communication between those of different visions is extremely difficult. As Sowell says after discussing some common terms like "equality" or "justice":
One consequence .. is that those with different visions often argue past each other, even when they accept the same rules of logic and utilize the same data, for the same terms of discourse signify very different things.
One of those very different things is process vs results. The unconstrained vision person will believe that some good, say "equality of income" can easily be directly achieved by adequately communicating it to the masses, and if needed simply "making it so" via redistribution of some sort. The constrained vision will believe that any such attempt will be highly likely to reduce the overall ability of the society to produce goods and end up leaving all worse off. They see "equality of income" as something barely of any use if the standard of living of the whole of society can be improved more reasonably by having inequality of income.
There are countless examples in the book of how various thinkers -- Rosseau, Smith, Jefferson, Hobbes, Hayek, Mill, Burke and fit into this framework and how it helps make sense of the vast differences in how people look at the same issues. The fact that most people will deny all manner of facts in order to maintain their vision is also covered.
For example, even though "National Socialism" in Germany had been widely praised by the unconstrained camp prior to WWII, the descent of something that they generally admired into a vicious totalitarian regime forced them to abandon their former name "socialists" and take the one that the constrained vision previously held "liberal". They changed their name, but they never changed their belief -- which of course is what actually led to the disaster in Germany, not the name.
I recommend the book very highly, and it is especially important in these times as the US seems to be shifting from a constrained vision (the one held by our founding fathers), again toward an unconstrained vision as we did under FDR and to a lesser degree during the LBJ "Great Society".
