At first it seems obvious, but the more you think about it the stranger the deductions from this axiom seem to become; in the end you cease to understand what is meant by it.

Although this may seem a paradox, all exact science is dominated by the idea of approximation. When a man tells you that he knows the exact truth about anything, you are safe in inferring that he is an inexact man. Every careful measurement in science is always given with the probable error ... every observer admits that he is likely wrong, and knows about how much wrong he is likely to be.

My whole religion is this: do every duty, and expect no reward for it, either here or hereafter.

Unless you assume a God, the question of life's purpose is meaningless.

There are some simple maxims which I think might be commended to writers of expository prose. First: never use a long word if a short word will do. So, if you want to make a statement with a great many qualifications, put some of the qualifications in separate sentences. Third: do not let the beginning of your sentence lead the reader to an expectation which is contradicted by the end.

If a philosophy is to bring happiness it should be inspired by kindly feelings. Marx pretended that he wanted the happiness of the proletariat; what he really wanted was the unhappiness of the bourgeois.

The fundamental defect of fathers, in our competitive society, is that they want their children to be a credit to them. We all feel instinctively, that our children's success reflect glory upon ourselves, while their failures make us feel shame. Unfortunately, the successes which cause us to swell with pride are often of an undesirable kind.... Neither happiness nor virtue, but worldly success, is what the average father desires for his children.