The fundamental principle in the analysis of propositions containing descriptions is this: Every proposition which we can understand must be composed wholly of constituents with which we are acquainted.

No great achievement is possible without persistent work.

The resistance to a new idea increases by the square of its importance.

I have found, for example, that if I have to write upon sum rather difficult topic, the best plan is to think about it with very great intensity-the greatest intensity of which I am capable-for a few hours or days, and at the end of that time give orders, so to speak (to my subconscious mind) that the work is to proceed underground. After some months I return consciously to the topic and find that the work has been done.

Order, unity, and continuity are human inventions, just as truly as catalogues and encyclopedias.

Organic life, we are told, has developed gradually from the protozoon to the philosopher, and this development, we are assured, is indubitably an advance. Unfortunately it is the philosopher, not the protozoon, who gives us this assurance.

Gradually, ... the aspect of science as knowledge is being thrust into the background by the aspect of science as the power of manipulating nature. It is because science gives us the power of manipulating nature that it has more social importance than art. Science as the pursuit of truth is the equal, but not the superior, of art. Science as a technique, though it may have little intrinsic value, has a practical importance to which art cannot aspire.