Yes, the first two are required to be truth. The third isn't technically required, especially for historical sciences. What *is* required is that the basic laws can be tested and those tests are repeatable. The specific application of those laws need not be repeatable.<quoted text>
Now we're getting somewhere. Why do you believe that only science can reveal truth? The scientific method can't solve or reveal every truth. For science to make a factual announcement about any event or process, there needs to be a foundational doctrine involved.
1) The subject must be observable.
2) The subject must be testable.
3) The subject test must be repeatable.
4) The testing process MUST BE HONEST!
The fourth condition is an important one. It is why the scientific method has a built-in error correction process. Some scientists have biases. Some instruments are incorrectly calibrated. Some experiments are ambiguous in their import.
The point is that any dishonesty will be revealed by further investigations by others. Any bad calibration will similarly be discovered. And ambiguous experiments will be refined to resolve the ambiguities. This isn't an instantaneous process. At times it is a long and laborious process. There can be many wrong turns and dead ends. Sometimes egos get in the way for years. But, eventually, the truth wins out *because* we require testability, observations, and repeatability.
If you have another way of finding truth that is better than the scientific method, please let us know. If you have found a way that can eliminate falsehoods and resolve disagreements better than testing through repeatable observations, this would be a wonderful thing.
What we know is that philosophy doesn't manage to do this. Philosophers are still arguing about the same things they were 2000 years ago. Religion doesn't do this. There are still violent disagreements about religion with no way to resolve them *because* no observations could do so. We know that intuition is fallible.
So, yes, in order to be called a *truth* as opposed to an *opinion*, I do require testable observations of basic principles. And that is the scientific method.