Karl Popper's work is of great diversity. It touches on virtually every intellectual activity. But he himself considered his philosophy of science one of his most important achievements. And indeed his achievement here is revolutionary. It destroyed the philosophy of inductivism which held sway over science for hundreds of years.

It should not surprise us that the recognition of this fact is resisted by most philosophical schoolmen. Usually the debate is carried out among philosophers. Their papers are philosophical papers and science comes in by way of interspersed examples. In this paper I shall try it the other way around, from the perspective of the scientist. I shall try to give you an account of my scientific field, the inquiry into the origin of life. And the philosophy of science will come in by way of interspersed references.

Before I come to my scientific story, let me briefly summarize and contrast the major tenets of inductivism and of Popper's deductivism (LSD, RAS, BG, CR). I begin with a caricature of inductivism in the form of eight theses:

1. Science strives for justified, proven knowledge, for certain truth.

2. All scientific inquiry begins with observations or experiments.

3. The observational or experimental data are organized into a hypothesis, which is not yet proven (context of discovery).

4. The observations or experiments are repeated many times.

5. The greater the number of successful repetitions, the higher the probability of the truth of the hypothesis (context of justification).

6. […]