But my conception 'white' does not change into my conception 'black.' On the contrary， it stays alongside of the objective blackness， as a different meaning in my mind， and by so doing lets me judge the blackness as the paper's change.Unless it stayed， I should simply say 'blackness' and know no more.Thus， amid the flux of opinions and of physical things， the world of conceptions， or things intended to be thought about， stands stiff and immutable， like Plato's Realm of Ideas.
Some conceptions are of things， some of events， some of qualities.Any fact， be it thing， event， or quality， may be conceived sufficiently for purposes of identification， if only it be singled out and marked so as to separate it from other things.Simply calling it 'this' or 'that' will suffice. To speak in technical language， a subject may be conceived by its denotation ， with no connotation ， or a very minimum of connotation， attached.The essential point is that it should be re-identified by us as that which the talk is about； and no full representation of it is necessary for this， even when it is a fully representable thing.
In this sense， creatures extremely low in the intellectual scale may have conception.All that is required is that they should recognize the same experience again.A polyp would be a conceptual thinker if a feeling of 'Hollo！ thingumbob again！' ever flitted through its mind.
Most of the objects of our thought， however， are to some degree represented as well as merely pointed out.Either they are things and events perceived or imagined， or they are qualities apprehended in a positive way.Even where we have no intuitive acquaintance with the nature of a thing， if we know any of the relations of it at all， anything about it， that is enough to individualize and distinguish it from all the other things which we might mean.Many of our topics of discourse are thus problematical ， or defined by their relations only.We think of a thing about which certain facts must obtain， but we do not yet know how the thing will look when it is realized.Thus we conceive of a perpetual-motion machine.It is a qu渟itum of a perfectly definite kind， - we can always tell whether the actual machines offered us do or do not agree with what we mean by it.The natural possibility or impossibility of the thing does not touch the question of its conceivability in this problematic way.'Round square，' 'black-white-thing，' are absolutely definite conceptions； it is a mere accident， as far as conception goes， that they happen to stand for things which nature lets us sensibly perceive. CONCEPTIONS ARE UNCHANGEABLE.The fact that the same real topic of discourse is at one time conceived as a mere 'that' or 'that which， etc.，' and is at another time conceived with additional specifications， has been treated by many authors as a proof that conceptions themselves are fertile and self-developing.A conception， according to the Hegelizers in philosophy， 'develops its own significance，'
'makes explicit what it implicitly contained，' passes， on occasion， 'over into its opposite，' and in short loses altogether the blankly self-identical character we supposed it to maintain.The figure we viewed as a polygon appears to us now as a sum of juxtaposed triangles； the number hitherto conceived as thirteen is at last noticed to be six plus seven， or prime；
the man thought honest is believed a rogue.Such changes of our opinion are viewed by these thinkers as evolutions of our conception， from within.
The facts are unquestionable； our knowledge does grow and change by rational and inward processes， as well as by empirical discoveries.Where the discoveries are empirical， no one pretends that the propulsive agency， the force that makes the knowledge develop， is mere conception.All admit it to be our continued exposure to the thing ， with its power to impress our senses.Thus strychnin， which tastes bitter， we find will also kill， etc.Now I say that where the new knowledge merely comes from thinking ， the facts are essentially the same， and that to talk of self-development on the part of our conceptions is a very bad way of stating the case.
Not new sensations， as in the em- pirical instance， but new conceptions， are the indispensable conditions of advance.
For if the alleged cases of self-development be examined it will be found， I believe， that the new truth affirms in every case a relation between the original subject of conception and some new subject conceived later on.These new subjects of conception arise in various ways.Every one of our conceptions is of something which our attention originally tore out of the continuum of felt experience， and provisionally isolated so as to make of it an individual topic of discourse.Every one of them has a way， if the mind is left alone with it， of suggesting other parts of the continuum from which it was torn， for conception to work upon in a similar way.This 'suggestion' is often no more than what we shall later know as the association of ideas.Often， however， it is a sort of invitation to the mind to play， add lines， break number-groups， etc.Whatever it is， it brings new conceptions into consciousness， which latter thereupon may or may not expressly attend to the relation in which the new stands to the old.Thus I have a conception of equidistant lines.Suddenly， I know not whence， there pops into my head the conception of their meeting.Suddenly again I think of the meeting and the equidistance both together， and perceive them incompatible." Those lines will never meet，" I say.Suddenly again the word 'parallel' pops into my head.'They are parallels，' I continue；
and so on.Original conceptions to start with； adventitious conceptions pushed forward by multifarious psychologic causes； comparisons and combinations of the two； resultant conceptions to end with； which latter may be of either rational or empirical relations.
