You may not like the idea that there is such a thing called the law of biogenesis and wish to reserve an exclusive use for the term law. That's fine, but all observation in the universe of real time shows that it is necessary and regular that life begets life. We can theorize or hypothesize otherwise. Until it is disproven, it holds. I'm happy to call it the principle of biogenesis. mware makes an appropriate point: "Given the concept that we must ACCEPT all theories, we would still believe in Spontaneous Generation instead of Biogenesis." This problem is somewhat inevitable, given the scientific style handed down from Descartes dictating that we must have certainty through the microscope of doubt.
In a court of law, laws don't always hold forever. That means, its necessity is subject to conditions. Many other kinds of similar principles have restrictive application.
Science, from earliest times, has endeavored to seek out those laws that are unconditional and unrestrictive. The term used to decribe such principles is "universal." It is logically questionable whether any science has for itself an "unrestricted universal domain." Obviously what Pasteur demonstrated has a restrictive application. I hope nobody doubts that.
That's fine, but similarly, all observations in the universe of real time shows that all things have a beginning. How do you reconcile this with ad infinitum application of "life begets life", unless you believe that life has always existed?