# John von Neumann quotes

### John von Neumann about Understanding, Mathematics, Competence

Young man, in mathematics you don't understand things. You just get used to them.
There's no sense in being precise when you don't even know what you're talking about.
It would appear that we have reached the limits of what it is possible to achieve with computer technology, although one should be careful with such statements, as they tend to sound pretty silly in 5 years.
If people do not believe that mathematics is simple, it is only because they do not realize how complicated life is.
The sciences do not try to explain, they hardly even try to interpret, they mainly make models. By a model is meant a mathematical construct which, with the addition of certain verbal interpretations, describes observed phenomena. The justification of such a mathematical construct is solely and precisely that it is expected to work - that is correctly to describe phenomena from a reasonably wide area. Furthermore, it must satisfy certain esthetic criteria - that is, in relation to how much it describes, it must be rather simple.
Anyone who attempts to generate random numbers by deterministic means is, of course, living in a state of sin.
It is just as foolish to complain that people are selfish and treacherous as it is to complain that the magnetic field does not increase unless the electric field has a curl. Both are laws of nature.