But it is true that observing that there are certain thoughts which arise neither from external objects nor from the determination of my will, but only from my faculty of thinking; in order to mark the difference between the ideas or the notions which are the forms of these thoughts, and to distinguish them from the others, which may be called extraneous or voluntary, I have called them innate.

But I have used this term in the same sense as when we say that generosity is innate in certain families; or that certain maladies, such as gout or gravel, are innate in others; not that children born in these families are troubled with such diseases in their mother's womb; but because they are born with the disposition or the faculty of contracting them."[22] His troublesome disciple, Regius, having asserted that all our ideas come from observation or tradition, Descartes remarks:-- "So thoroughly erroneous is this assertion, that whoever has a proper comprehension of the action of our senses, and understands precisely the nature of that which is transmitted by them to our thinking faculty, will rather affirm that no ideas of things, such as are formed in thought, are brought to us by the senses, so that there is nothing in our ideas which is other than innate in the mind (_naturel a l'esprit_), or in the faculty of thinking, if only certain circumstances are excepted, which belong only to experience.

For example, it is experience alone which causes us to judge that such and such ideas, now present in our minds, 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.