Dear Stefan-Ivan,
Steve offers a helpful definition.
I found it also helpful to study the 'glossary' which Bishop Kallistos placed at the back of the volunes of the english "Philokalia". It is very helpful when we read some of these texts to refer to his explanations.
In the glossary, 'Noetic' is defined as "that which belongs to or is characteristic of the intellect".
But this definition is so much better understood when we also read his entry for 'Intellect' which he says is "the highest faculty in man, through which -- provided it is purified -- he knows God or the inner essences or principles of created things by means of direct apprehension or spiritual perception. Unlike the 'dianoia' or 'reason', from which it must be carefully distinguished, the intellect does not function by formulating abstract concepts and then arguing on this basis to a conclusion reached through deductive reasoning, but it understands divine truth by means of immediate experience, intuition or 'simple cognition' (the term used by Saint Isaac the Syrian). The intellect dwells in the 'depths of the soul'; it constitutes the innermost aspect of the heart (Saint Diadochos). The intellect is the organ of contemplation, the 'eye of the heart' (Makarian homilies)."
With best wishes for your reading and study!
