Descartes, Rene - Causes of ideas
Type of Spiritual Experience
Principally about inspiration and wisdom, but he also mentions forms as such there is also the notion of templates as archetypal images of forms.
This is key philosophically as it says that all ideas if we trace them back far enough, owe their origin to an idea outside of ourselves and humanity at large - in effect they belong to the spirit world, we discover ideas, we are explorers of other realms spiritual.
A description of the experience
Rene Descartes – Key Philosophical Writings
And although it may be the case that one idea gives birth to another idea, that cannot continue to be so indefinitely; for in the end we must reach an idea whose cause shall be so to speak, an archetype, in which the sole reality which is … objectively in these ideas is contained formally. Thus the light of nature causes me to know clearly that the ideas in me are like pictures or images which can , in truth, easily fall short of the perfection of the objects from which they have been derived, but which can never contain anything greater or more perfect.
And the longer and the more carefully that I investigate these matters, the more clearly and distinctly do I recognise their truth. But what am I to conclude from all of it in the end? It is this, that if the objective reality of any one of my ideas is of such a nature as clearly to make me recognise that it is not in me either formally or eminently, and that consequently I cannot myself be the cause of it, it follows of necessity that I am not alone in the world, but that there is another …... cause of this idea