Observation, reason, and experiment make up what we call the scientific method.

To decide upon the answer is not scientific. In order to make progress, one must leave the door to the unknown ajar ajar only.

You can’t say A is made of B or vice versa. All mass is interaction.

We absolutely must leave room for doubt or there is no progress and there is no learning. There is no learning without having to pose a question. And a question requires doubt. People search for certainty. But there is no certainty. People are terrified — how can you live and not know? It is not odd at all. You only think you know, as a matter of fact. And most of your actions are based on incomplete knowledge and you really don’t know what it is all about, or what the purpose of the world is, or know a great deal of other things. It is possible to live and not know.

We cannot define anything precisely. If we attempt to, we get into the paralysis of thought that comes to philosophers, who sit opposite each other, one saying to the other, "You don't know what you are talking about!" The second one says, "What do you mean by know? What do you mean by talking? What do you mean by you?"

It is simple, therefore it is beautiful

The "paradox" is only a conflict between reality and your feeling of what reality "ought to be."