"The infinite number of questions asked in every sphere of human culture can be reduced to three general, fundamental questions.
These questions contain many more detailed, more elaborately phrased questions, which can be expressed in complex philosophical forms, or spelled out through professional scientific analysis.
These questions relate to both the simplest objects encountered in everyday life and to complex cultural or scientific systems; to concrete objects and realities that people cannot help but notice, and to creations of the mind, whose actual existence is uncertain.
These three questions may be summarized in very simple words:
In more abstract language we can say:
What is the question about the essence of things, their definition and identity, and their relationship to other entities.
How is the question of the reason for things: Why do things happen the way they do, what brings about their existence, and what causes various events?
What For is the question of purpose: What is the purpose for which certain things are done, or exist?
One can cast doubts on the philosophical validity of these questions, and there are surely areas in which these questions can be considered meaningless.
Nevertheless, these three questions are undoubtedly fundamental ones which human beings, qua human beings, ask, and try to resolve."
From "Science, Mathematics, and Religion," a lecture delivered at the Russian Academy of Sciences, Department of Space Sciences, 1988