Charles Sanders Peirce is one of my favourite philosophers, but one whose writings are difficult to get into. This is partly because the corpus of his thought consists of unpublished notes and partly because of his tendency to fly off on tangents when he is outlining an argument. I often find it useful to examine suggestive fragments of his thought as points of departure. To this end, I present here a few of my favourite quotations, in the hope that they might spark a similar curiosity. (The citations are from the Harvard editions of his complete works)

It is certainly important to know how to make our ideas clear, but they may be ever so clear without being true 5.410

All this universe is perfused with signs, if it is not composed exclusively of signs. 4.539

That truth and justice are great powers in the world is no figure of speech, but a plain fact to which theories must accommodate themselves. 1.348

That which gives actuality is opposition. We can only know facts by their acting upon us, and resisting our brute will. 1.432

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 great fortune, as every dynasty, as every civilization does. In place of this we have death. 2.653

The idea that we can immediately perceive only what is present seems to be founded on our ordinary experience that we cannot recall and reexamine the events of yesterday nor know otherwise than by inference what is to happen tomorrow. Obviously, then, the first move toward beating idealism at its own game is to remark that we apprehend our own ideas only as flowing in time, and since neither the future nor the past, however near they may be, is present, there is as much difficulty in conceiving our perception of what passes within us as in conceiving external perception. An immediate, intuitive consciousness of time clearly exists wherever time exists. But once one grants immediate knowledge in time what becomes of the idealist theory that we immediately know only the present? For the present can contain no time. 1.38

Good morals and good manners are identical, except that tradition attaches less importance to the latter. 1.50.

The effect of mixing speculative inquiry with questions of conduct results finally in a sort of half make-believe reasoning which deceives itself in regard to its real character... Men tell themselves they regulate their conduct by reason; but they learn to look forward and see what conclusions a given method will lead to before they give their adhesion to it. In short, it is no longer the reasoning which determines what the conclusion shall be, but it is the conclusion which determines what the reasoning shall be. 1.56.

Conscience really belongs to the subconscious man, to that part of the soul which is hardly distinct in different individuals, a sort of community-consciousness, or public spirit, not absolutely one and the same in different citizens, and yet not by any means independent in them. Conscience has been created by experience just as any knowledge is; but it is modified by further experience only with secular slowness. 1.56

True science is distinctively the study of useless things. For the useful things will get studied without the aid of scientific men. To employ these rare minds on such work is like running a steam engine by burning diamonds. 1.76.

The evolutionary theory in general throws great light upon history and especially upon the history of science -- both its public history and the account of its development in an individual intellect. As great a light is thrown upon the theory of evolution in general by the evolution of history, especially that of science. 1.103 .

It is to be noted that existence is an affair of blind force. "The very hyssop that grows on the wall exists in that chink because the whole universe could not prevent it." 1.329.

Though "desire" implies a tendency to volition, and though it is a natural hypothesis that a man cannot will to do that which he has no sort of desire to do, yet we all know conflicting desires but too well, and how treacherous they are apt to be; and a desire may perfectly well be discontented with volition, i.e., with what the man will do. The consciousness of that truth seems to me to be the root of our consciousness of free will. "Involuntary attention" involves in correct English a contradiction in adjecto. 1.331

Some writers insist that all experience consists in sense-perception; and I think it is probably true that every element of experience is in the first instance applied to an external object. A man who gets up out of the wrong side of the bed, for example, attributes wrongness to almost every object he perceives. That is the way in which he experiences his bad temper. It cannot, however, be said that he perceives the perversity which he wrongly attributes to outward objects. 1. 335.

To be angry with sceptics, who, whether they are aware of it or not, are the best friends of spiritual truth, is a manifest sign that the angry person is himself infected with scepticism. 1.344

All thinking is dialogic in form. Your self of one instant appeals to your deeper self for his assent. Consequently, all thinking is conducted in signs that are mainly of the same general structure as words (symbols) these consist of conventional signs that bare no relation to thier object except by association of habit. 6.338.

Signs, are the only things with which a human being can, without derogation, consent to have any transaction with. The human being is in fact a sign himself. 6.344 .

Existence is a special mode of reality, which, whatever other characteristics it possesses, has that of being absolutely determinate. Reality, in its turn, is a special mode of being, the characteristic of which is that things that are real are whatever they really are, independently of any assertion about them. 6.348

If Man is the measure of things, as Protagoras said, then there is no complete reality; but being there certainly is, even then. 6.348

At first sight it seems no doubt a paradoxical statement that, "The object of final belief which exists only in consequence of the belief, should itself produce the belief"; but there have been a great many instances in which we have adopted a conception of existence similar to this. 7. 340

If it be asked us, whether some realities do not exist, which are entirely independent of thought; I would in turn ask, what is meant by such an expression and what can be meant by it? It is clear that it is quite beyond the power of the mind to have an idea of something entirely independent of thought. 7.345

Metaphysics is a subject much more curious than useful, the knowledge of which, like that of a sunken reef, serves chiefly to enable us to keep clear of it. 5.410

Consider what effects, that might conceivably have practical bearings, we conceive the object of our conception to have. Then, our conception of these effects is the whole of our conception of the object. 5.2

The essence of truth lies in its resistance to being ignored. 2.139

The first questions which men ask about the universe are naturally the most general and abstract ones. Nor is it true, as has so often been asserted, that these are the most difficult questions to answer. 1.152

[There is a] common aversion to recognizing thought as an active factor in the real world. 1.348.

Those problems that at first blush appear utterly insoluble receive, in that very circumstance.. their smoothly-fitting keys. 6.460

Higher weapons in the arsenal of thought are not playthings but edge-tools. 6.461

With your eyes open, awake to what is about or within you, and open conversation with yourself; for such is all meditation. It is, however, not a conversation in words alone, but is illustrated, like a lecture, with diagrams and with experiments. 6.461

[I]t is almost always found that when a new idea is born into the living world of thought, it labors under all sorts of inconsequential and inconvenient adjuncts. A new machine, for example, is at first needlessly complicated, and has to be simplified later. 4.661

Pragmaticism is not a system of philosophy. It is only a method of thinking 8.206

Every unidealistic philosophy supposes some absolutely inexplicable, unanalyzable ultimate; in short, something resulting from mediation itself not susceptible of mediation. Now that anything is thus inexplicable can only be known by reasoning from signs. But the only justification of an inference from signs is that the conclusion explains the fact. To suppose the fact absolutely inexplicable, is not to explain it, and hence this supposition is never allowable.

5.265