In praise of concrete

Political theory through the centuries, in all its many forms, shares one essential feature. Every theory gets lost in fluffy metaphysical clouds.
Whatever the principle be it liberalism, utilitarianism, communism - they are all false because none can capture the complexity of human society with anything like the degree of accuracy which is adequate to predict the outcome of the change.
When making political choices stick as far as you can to what can be experienced, to what can be weighed or to what can be measured. Avoid the abstract!
For example. Do not look at humanity - look at the indidual men, women and children. Do not think about society - think of the flesh and blood. Slavery, for example, is not evil because it infringes human rights. slavery is evil because of what it does to the individual human being syanding in front of you.