Digital Companion to C. S. Peirce
1895 [c.] | On Quantity, with special reference to Collectional and Mathematical Infinity | NEM 4:267

Logic and metaphysics make no special observations; but they rest upon observations which have been made by common men. Metaphysics rests upon observations of real objects, while logic rests upon observations of real facts about mental products, such as that, not merely according to some arbitrary hypothesis, but in every possible case, every proposition has a denial, that every proposition concerns some objects of common experience of the deliverer and the interpreter, that it applies to that some idea of familiar elements abstracted from the occasions of the excitation, and that it represents that an occult compulsion not within the deliverer’s control unites that idea to those objects. All these are results of common observation, though they are put into scientific and uncommon groupings.

1895 [c.] | On Quantity, with special reference to Collectional and Mathematical Infinity | NEM 4:273

Philosophy, which makes no special observations, but uses facts commonly known. In order to be exact, it must rest on mathematical principles. It divides into Logic, which studies the world of thought, and Metaphysics, which studies the world of being; and the latter must rest upon the principles of the former.

1898 | Cambridge Lectures on Reasoning and the Logic of Things: Philosophy and the Conduct of Life | EP 2:36

Philosophy seems to consist of two parts, Logic and Metaphysics. [—]

Metaphysics recognizes an inner and an outer world, a world of time and a world of space. The special sciences, all that follow after Metaphysics divide themselves into Psychics and Physics.

1902 [c.] | Minute Logic: Chapter II. Prelogical Notions. Section I. Classification of the Sciences (Logic II) | CP 1.282

metaphysics, whose attitude toward the universe is nearly that of the special sciences (anciently, physics was its designation), from which it is mainly distinguished, by its confining itself to such parts of physics and of psychics as can be established without special means of observation. But these are very peculiar parts, extremely unlike the rest.

1903 | Harvard Lectures on Pragmatism: Lecture II | EP 2:146-147

… Philosophy ought to be regarded as having three principal divisions. Its principal utility, although by no means its only utility, is to furnish a Weltanschauung, or conception of the universe, as a basis for the special sciences. Metaphysics is the final branch of philosophical inquiry whose business it is to work this out. But metaphysics must rest upon normative sciences.

1903 | Harvard Lectures on Pragmatism: Lecture V | EP 2:196-197

Philosophy has three grand divisions. The first is Phenomenology, which simply contemplates the Universal Phenomenon and discerns its ubiquitous elements, Firstness, Secondness, and Thirdness, together perhaps with other series of categories. The second grand division is Normative Science, which investigates the universal and necessary laws of the relation of Phenomena to Ends, that is, perhaps, to Truth, Right, and Beauty. The third grand division is Metaphysics, which endeavors to comprehend the Reality of Phenomena. Now Reality is an affair of Thirdness as Thirdness, that is, in its mediation between Secondness and Firstness.

1903 | Syllabus: Syllabus of a course of Lectures at the Lowell Institute beginning 1903, Nov. 23. On Some Topics of Logic | EP 2:259-260

Philosophy is divided into (a) Phenomenology; (b) Normative Science; (c) Metaphysics.

Phenomenology ascertains and studies the kinds of elements universally present in the phenomenon; meaning by the phenomenon, whatever is present at any time to the mind in any way. Normative science distinguishes what ought to be from what ought not to be, and makes many other divisions and arrangements subservient to its primary dualistic distinction. Metaphysics seeks to give an account of the universe of mind and matter. Normative science rests largely on phenomenology and on mathematics; metaphysics on phenomenology and on normative science. [—]

Metaphysics may be divided into (i) General Metaphysics, or Ontology; (ii) Psychical, or Religious, Metaphysics, concerned chiefly with the questions of (1) God, (2) Freedom, (3) Immortality; and (iii) Physical Metaphysics, which discusses the real nature of Time, Space, Laws of Nature, Matter, etc. The second and third branches appear at present to look upon one another with supreme contempt.

1903 [c.] | Unidentified Fragments | CP 6.6

Metaphysics is the proper designation for the third, and completing department of coenoscopy, which in places welds itself into idioscopy, or special science.

1903 [c.] | A fragment on metaphysics [CP] | CP 6.6

Metaphysics is the proper designation for the third, and completing department of coenoscopy, which in places welds itself into idioscopy, or special science.

1904 | A Brief Intellectual Autobiography by Charles Sanders Peirce | Peirce, 1983, pp. 71-72; MS [R] L107:19, 21

Metaphysics is still more special [compared to normative science], only considering the phenomenon in so far as it is a sign of what is real. [—] [U]nder the head of metaphysics will be included, not merely ontology, but also whatever philosophy can determine respecting causation, the freedom of the will, the connection of mind and matter, optimism or pessimism, immortality, theology, time and space, etc.

1904 | Reason's Conscience: A Practical Treatise on the Theory of Discovery; Wherein logic is conceived as Semeiotic | NEM 4:192; HP 2:825

Metaphysics is that branch of philosophy which inquires into what is real, that is, what has anything true of it regardless of whether anybody thinks it is true or not.

1906 | The Basis of Pragmaticism | EP 2:375

Metaphysics is the proper designation for the third and completing department of cenoscopy, which in places welds itself into idioscopy, or special science. Its business is to study the most general features of reality and real objects. [—] Here let us set down almost at random a small specimen of the questions of metaphysics which press, not for hasty answers, but for industrious and solid investigation: …

1909 | A Sketch of Logical Critics | EP 2:459

… Under Philosophy, we shall find ourselves again forced,-unless we wrench matters,-to make a trichotomy; recognizing first, Phenomenology; second, the Critical, Normative Sciences, and third, Metaphysics, the science of Reality.

nd | A Suggested Classification of the Sciences | MS [R] 1339:12

Metaphysics […] seeks to explain the constitution of the Physio-Psychical Universe.