re either ideas actually imprinted on the senses or else such as are perceived by attending to the passions and operations of the Mind, or lastly idea

ion." "In the case of the definitions of Geometry there exist no real things exactly conformable to the definitions." Again Taine, "Les images sont les exactes reproductions de la sensation." Again Diderot, "Pour imaginer il faut colorer un fond et détacher de ce fait des points en leur supposant une couleur differente de celle du fond. Restituez à ces points la même couleur

d are originally furnished to it by sensation, from which therefore are derived, not necessarily a

t we derive our fundamental conceptions of the external world; that sensations only mark the interruptions in the dynamic Activity in whi

become the instruments of Knowledge. We propose rather to turn to the principal ideas of the external world which a

dge of the external must be thence derived. But such a use of the term is loose, misleading, and infrequent. The only safe course is to confine the term Sensation to the immediate data of the five senses-touch, sig

he idea of Time is not derived from the external world at all, but is furnished to us directly by the operations of the Mind, and that therefore its intellectual origin need not involve any exception to the general rule that th

of our Knowledge must be obliged to affirm the possibility of sensations of Space. Mach indeed claims to distinguish physiological Space, geometrical Space, visual Space, tactual Space as all different and yet apparently harmoniously blended in our Experience. He is, however, sadly wanting in clearness

on in terms? Pure Space, if it means anything, means absolute material emptiness and vacuity. How, then, by any possibilit

ven it involves a negative. The term "free" is in reality, though not in form, a negative term and means "unconstrained." And the reason why such a term is necessarily negative is to be found in the fact that a state of dynamic constraint is the essen

Space. It proves that the idea of Space is a representation of one condition of our Activity. It is because the primary wo

ill readily be agreed that if this is so of any sensations it is pre-eminently true of the sensations of vision and touch. Indeed, it will perhaps not be disputed that the ordinary vident man derive

each distinct from its adjacent neighbour, yet all inter-related as parts of

ry long time to encounter in touch, are presented simultaneously. In this there is an immense practical advantage, the result being that we come habitually to direct our every action by reference to the data of Sight. Now it is because these data-so simultaneously presented-are employed by us as the guides of action that their presentation acquires the character which we denominate Extensity. The simultaneous occurrence of a large number of Sounds does not se

s the instrument of our Activity and the guide of Action that it acquires the character

e. But light also and in addition is reflected from, and thus reveals the presence of the whole body of our resistant environment. Hence is derived the coloured presentation of Vision to which the character of extensity attaches. Nothing similar takes place in the case of the other distantial sensations. If sonorous undulations excited vibration in every resistant object of

learn of the experiences of the blind. Nowhere have we found this aspect of the question discussed with the sa

at the modalities of the action of the blind are explained by spatial representations. These must be derived from touch. What, then, can be the spatial representations which arise from touch? The blind, he says, are often asked, How do you figure to yourself such and such an object, a chair, a table, a triangle? M. Villey quotes Diderot as affirming that the blind cannot imag

le décalque de la sensation, and he refers not merely to Condillac the frien

sations occupy an extended space which the blind in thought can add t

ive tactual palpations. But he maintains that the evidence of the blind is unanimous on this point, that once formed in the mind the idea of the chair presents itself to him immediately as a whole,-the order in which its features were ascertained is not preserved, and does not require to be repeated. Indeed, the idea divests itself of the great bulk of the tactual details by which it was apprehended, whilst the muscular sensations which accompanied the act of pal

th impracticable and unnecessary, and would involve such a sacrifice of time as to render Discourse altogether impossible. All that the Mind of the vident ordinarily grasps and utilises in his discursive employment of the idea of any phys

ns which that Activity perpetually encounters, and in which sensations arise. It would indeed be a useful work of psychological analysis if the conditions of exertion

ements of such a

distinction between Up and Down from which as a starting-point we build up our conception of tridimensional Space. And in this respect it must be remembered that as the areas of spheres are proportional to the squares of their radii it necessarily f

d therefore the form of material bodies. These, therefore, are necessarily subject also to tridimensiona

rmines all our movements, and in which we discover those forms

eterminant of activity, and thus

ch its action must conform, and which necessarily also partake of, and help us to conceive of tridimensional form. It is interesting to note tha

of action is also well illustrated in the case of the blind, and to this also M. Villey

active touch. Just as we distinguish between hearing and listening, betwee

t comparatively little. It is necessary to explore; that is

wnwards. Palpation by the fingers marks a further stage. The blind also, we

lication of different parts of the hand on the surface of a body, the latter that which we owe to the movements of our fingers when having only one point of contact with the object the fingers follow its contour. Various examples of the delicacy

ion derived from walking and other movements of the lower limbs, and then to the co-ordination of the

mmon element cannot possibly be supplied either by the data of visual sensation which the blind do not possess, or by the data of passive tactual sensation which the vident hardly ever employ. Une étendue commune se retrouverait à la fois dans le

operate constantly, is originally known to us in the stress or pressure to which muscular exertion in contact with a material body gives rise. Such a force if it could be co

rue estimate of the Energy of a body moving under the impulse of a constant Force is stated in the formula 1/2MV2. To ascertain M, th

scular energy required to effect the motion in question, thereafter objectively and scientifically by comparison with some independent standard where

otent actors, and the recognition of this great truth provides us with the means of clearly app

just that a percept is a concept associated with the dyn

questions which have been raised as to the distinction b

racted from this dynamic reference. Thus white is concrete because colour is a property of the dynamic world. But when this property is considered apart from its dynamic support it is called whiteness, and becomes abstract. In the case of purely mental qualities the term is regarded as abstract simply

a purely abstract term. But as the word takes up a dynamic reference so does its abstraction diminish. Thus in the expression "Administ

er se it possesses no spatial or extensive or external suggestiveness; that sensations nevertheless serve to denote or give feature and particularity to our experience of activity; that all perception of the external is at bottom therefore a mental representation of exertional activity and its forms, denoted, punctuated, identified by sensation, whi

TNO

ference to our organism. This, of course, means by reference to the