ds, are
related to certain things which are external to us; not in truth,
that they have been sent into our mind by these things, such as
they are, by the organs of the senses; but because these organs
have transmitted something which has occasioned the mind, in virtue
of its innate power, to form them at this time rather than at
another....

"Nothing passes from external objects to the soul except certain
motions of matter (_mouvemens corporels_), but neither these
motions, nor the figures which they produce, are conceived by us as
they exist in the sensory organs, as I have fully explained in my
"Dioptrics"; whence it follows that even the ideas of motion and of
figures are innate (_naturellement en nous_). And, _a fortiori_,
the ideas of pain, of colours, of sounds, and of all similar things
must be innate, in order that the mind may represent them to
itself, on the occasion of certain motions of matter with which
they have no resemblance."

Whoever denies what is, in fact, an inconceivable proposition, that
sensations pass, as such, from the external world into the mind, must
admit the conclusion here laid down by Descartes, that, strictly
speaking, sensations, and _a fortiori_, all the other contents of the
mind, are innate. Or, to state the matter in accordance with the views
previously expounded, that they are products of the inherent properties
of the thinking organ, in which they lie potentially, before they are
called into existence by their appropriate causes.

But if all the contents of the mind are innate, what is meant by
experience?

It is the conversion, by unknown causes, of these innate potentialities
into actual existences. The organ of thought, prior to experience, may
be compared to an untouched piano, in which it may be properly said that
music is innate, inasmuch as its mechanism contains, potentially, so
many octaves of musical notes. The unknown cause of sensation which
Descartes calls the "je ne sais quoi dans les objets" or "choses telles
qu'elles sont," and Kant the "Noumenon" or "Ding an sich," is
represented by the musician; who, by touching the keys, converts the
potentiality of the mechanism into actual sounds. A note so produced is
the equivalent of a single experience.

All the melodies and harmonies that proceed from the piano depend upon
the action of the musician upon the keys. There is no internal