From the philosophical and historical stands the paper analyzes Peirce’s critical project of metaphysics. Peirce’s alternative names for metaphysics are phenomenology or phaneroscopy. Metaphysics, as the science of reality, rests on the absolute acceptance of logical principles as truths of being, and also on experience and facts (logic is the key of philosophy). It was Peirce’s idea that the foundations of metaphysics would be better understood if the dependence of metaphysics on observations were generally known. Fundamental metaphysical categories are the modes of being and the modes of existence. New metaphysics has to be constructed as a rigorous science - this is the main objection to the old concept of metaphysics. As for the spirit in which Peirce advanced his own cosmogonic principle in metaphysics, nothing can be more certain in the whole of Percian exegesis than that he believed this principle to express the interests of the free spirit of science itself.