We must, however, distinguish between two aspects of the rational soul, to one of which alone the above statements apply. Thought differs from sensation in that the latter perceives the particular form of the individual thing, whereas the former apprehends the essential nature of the object, that which constitutes it a member of a certain class. The sense of sight perceives a given individual man; thought or reason understands what it is to be a member of the human species. Reason therefore deals with pure form. In man we observe the reason gradually developing from a potential to an actual state. The objects of the sense with the help of the faculties of sensation, memory and imagination act upon the potential intellect of the child, which without them would forever remain a mere capacity without ever being realized. This aspect of the reason then in man, namely, the passive aspect which receives ideas, grows and dies with the body. But there is another aspect of the reason, the active reason which has nothing to do with the body, though it is in some manner resident in it during the life of the latter. This it is which enables the passive intellect to become realized. For the external objects as such are insufficient to endow the rational capacity of the individual with actual ideas, any more than a surface can endow the sense of sight with the sensation of color when there is no light. It is the active intellect which develops the human capacity for thinking and makes it active thought. This alone, the active intellect, is the immortal part of man. This very imperfect sketch of Aristotle's mode of approach to the ever-living problems of God, the universe and man shows us the wide diversity of his method from that with which the Jews of Biblical and Rabbinic tradition were identified. Greek philosophy must have seemed a revelation to them, and we do not wonder that they became such enthusiastic followers of the Stagirite, feeling as they must have done that his method as well as his results were calculated to enrich their intellectual and spiritual life. Hence the current belief of an original Jewish philosophy borrowed or stolen by the Greeks, and still betraying its traces in the Bible and Talmud was more than welcome to the enlightened spirits of the time. And they worked this unhistorical belief to its breaking point in their Biblical exegesis. Aristotle, however, was not their only master, though they did not know it. Plotinus in Aristotelian disguise contributed not a little to their conception of God and his relation to the universe. The so-called "Theology of Aristotle"[25] is a Plotinian work, and its Pantheistic point of view is in reality foreign to Aristotle's dualism. But the middle ages were not aware of the origin of this treatise, and so they attributed it to the Stagirite philosopher and proceeded to harmonize it with the rest of his system as they knew it.