Charles Sanders Peirce Quotes

Do not block the way of inquiry.

We think only in signs.

By an object, I mean anything that we can think, i.e. anything we can talk about.

In fact, this infinitesimally spread-out consciousness is a direct feeling of its contents as spread out. In an infinitesimal interval we directly perceive the temporal sequence of its beginning, middle, and end... Now upon this interval follows another, whose beginning is the middle of the former, and whose middle is the end of the former. Here we have an immediate perception of the temporal sequence of its beginning, middle and end, or say, of the second, third, and fourth instants.

All human affairs rest upon probabilities, and the same thing is true everywhere. If man were immortal, he could be perfectly sure of seeing the day when everything in which he had trusted should betray his trust, and, in short, of coming eventually to hopeless misery. He would break down, at last, as every good fortune, as every dynasty, as every civilization does. In place of this we have death. But what, without death, would happen to every man, with death must happen to some man . . . It seems to me that we are driven to this, that logicality inexorably requires that our interests shall not be limited. They must not stop at our own fate, but must embrace the whole community.

Upon this first, and in one sense this sole, rule of reason, that in order to learn you must desire to learn, and in so desiring not be satisfied with what you already incline to think, there follows one corollary which itself deserves to be inscribed upon every wall of the city of philosophy: Do not block the way of inquiry.

The quality of feeling is the true psychical representative of the first category of the immediate as it is in its immediacy, of the present in its direct positive presentness. Qualities of feeling show myriad-fold variety, far beyond what the psychologists admit. This variety however is in them only insofar as they are compared and gathered into collections. But as they are in their presentness, each is sole and unique; and all the others are absolute nothingness to it — or rather much less than nothingness, for not even a recognition as absent things or as fictions is accorded to them. The first category, then, is Quality of Feeling, or whatever is such as it is positively and regardless of aught else.

In deduction the mind is under the dominion of a habit or association by virtue of which a general idea suggests in each case a corresponding reaction. This is the way the hind legs of a frog separated from the rest of the body, reason, when you pinch them. It is the lowest form of psychical manifestation.

If a man burns to learn and sets himself to comparing his ideas with experimental results in order that he may correct those ideas, every scientific man will recognize him as a brother, no matter how small his knowledge may be.

I call a sign which stands for something merely because it resembles it, an icon. Icons are so completely substituted for their objects as hardly to be distinguished from them. Such are the diagrams of geometry. A diagram, indeed, so far as it has a general signification, is not a pure icon; but in the middle part of our reasonings we forget that abstractness in great measure, and the diagram is for us the very thing. So in contemplating a painting, there is a moment when we lose the consciousness that it is not the thing, the distinction of the real and the copy disappears, and it is for the moment a pure dream, — not any particular existence, and yet not general. At that moment we are contemplating an icon.

Since space is continuous, it follows that there must be an immediate community of feeling between parts of mind infinitesimally close together. Without this, I believe it would have been impossible for any co-ordination to be established in the action of the nerve-matter of one brain.

We have here a question of difficulty, analogous to the question of nominalism and realism.

The entire universe is perfused with signs, if it is not composed exclusively of signs.

Abduction is the process of forming an explanatory hypothesis. It is the only logical operation which introduces any new idea; for induction does nothing but determine a value and deduction merely evolves the necessary consequences of a pure hypothesis.

Let us not pretend to doubt in philosophy what we do not doubt in our hearts.