The essay offers an explanation of the most important Peirce’s steps on his way to scientific metaphysics. His philosophy might be described as a conceptual reconstruction of the universe using the methods of science. Logic and methodology and their place in the construction of the new philosophy, i.e. Peirce’s scientific metaphysics, are outlined as well. Fallibilism and abduction are among the means needed to achieve this objective. Peirce suggests that the key to the explanation of active human condition is the philosophy of pragmaticism.