We can never know anything.
Nature allows only experimental situations to occur which can be described within the framework of the formalism of quantum mechanics.
Nature is made in such a way as to be able to be understood. Or perhaps I should put it-more correctly-the other way around, and say that we are made in such a way as to be able to understand Nature.
We will have to abandon the philosophy of Democritus and the concept of elementary particles. We should accept instead the concept of elementary symmetries.
The basic idea is to shove all fundamental difficulties onto the neutron and to do quantum mechanics in the nucleus.
Even for the physicist the description in plain language will be a criterion of the degree of understanding that has been reached.
The exact sciences also start from the assumption that in the end it will always be possible to understand nature, even in every new field of experience, but that we may make no a priori assumptions about the meaning of the word understand.
In general, scientific progress calls for no more than the absorption and elaboration of new ideas- and this is a call most scientists are happy to heed.
The Same organizing forces that have shaped nature in all her forms are also responsible for the structure of our minds.
Natural science, does not simply describe and explain nature; it is part of the interplay between nature and ourselves.
Every word or concept, clear as it may seem to be, has only a limited range of applicability.
It is probably true quite generally that in the history of human thinking the most fruitful developments frequently take place at those points where two different lines of thought meet.
A consistent pursuit of classical physics forces a transformation in the very heart of that physics.
The solution of the difficulty is that the two mental pictures which experiment lead us to form – the one of the particles, the other of the waves – are both incomplete and have only the validity of analogies which are accurate only in limiting cases.
The positivists have a simple solution: the world must be divided into that which we can say clearly and the rest, which we had better pass over in silence. But can anyone conceive of a more pointless philosophy, seeing that what we can say clearly amounts to next to nothing? If we omitted all that is unclear, we would probably be left completely uninteresting and trivial tautologies.
Whether we like it or not, modern ways are going to alter and in part destroy traditional customs and values.
I am firmly convinced that we must never judge political movements by their aims, no matter how loudly proclaimed or how sincerely upheld, but only by the means they use to realize these aims.
In classical physics, science started from the belief – or should one say, from the illusion? – that we could describe the world, or least parts of the world, without any reference to ourselves.
Here the attention of the research workers is primarily directed to the problem of reconciling the claims of the special relativity theory with those of the quantum theory. The extraordinary advances made in this field by Dirac... leave open the question whether it will be possible to satisfy the claims of the two theories without at the same time determining the Sommerfeld fine-structure constant.
The renouncing of life and immediacy, which was the premise for the progress of natural science since Newton, formed the real basis for the bitter struggle which Goethe waged against the physical optics of Newton. It would be superficial to dismiss this struggle as unimportant: there is much significance in one of the most outstanding men directing all his efforts to fighting against the development of Newtonian optics.