427a19-21: Thinking and understanding are thought to be like a form of perceiving (for in both of these the soul judges and recognizes some existing thing).
Thinking (noein) and understanding (phronein) seem to refer to the theoretical and practical knowledge.
But this is an inappropriate distinction in the context of discussing the common beliefs, as it is the case in this passage. Even if Aristotle reads the common sense in his own terms, he could not impose to the common sense a distinction based on the philosophical inquiries into human psychology.
Phronein is practical thought as long as it provides the understanding of the pragma surrounding human life. It is not bulked together with human activities, but gives them the character of being forms of apprehending the reality. Hence, the common idea of Greek morality that to be moral means to understand your truly nature.
For ‘thinking and understanding are thought’, Greek uses the verb dokein, also translatable as to seem or to pretend. The related noun is used by Euripides for a vision, an appearance, or a phantom. Nonetheless, dokein is close to dechomai, to receive. We may take dokein used here as a mark of Aristotle’s contempt to the confusion between soul faculties. But also, we may infer that common sense refers to thought in the fashion of receiving what it happens to it, or how can impose itself to us in spite of our practice of neglecting an alien thing as it is others’ thought, or even our thought. For our thought, at least because of its different tempo than that of our actions, resists to the tendency of taking it as a simple ingredient of our activity.
They ‘appear to be like’ – dokein hosper -. If something has the power to appear, to become visible, that means that it is not entirely abstruse as one belonging to a different reality than that we commonly seize. A thing immersed in our current life becomes a strictly theoretical object only by a previous work of the theoretician to expel the ways in which life is common to anybody and incompatible, for this reason, to any pretence of pulling out the things from reality for moving them in a theoretical realm.
And Aristotle considers thinking and understanding as being like perceiving, meaning that their at hand presence in the reality of the word takes the form of perceiving, aisthanesthai. And the Greek aisthaneisthai sends us again to the domain of appearance, of seeing, of feeling, but also of understanding and learning. With these senses, aistaneisthai cannot simply means a bodily process of receiving impressions. It is rather the way by which we exercise ourselves in the reality of things as a process of learning.
The world is learned by perceiving it, implying the consequence that a thing learnt ceases to keep alive our interest in it. The interest passes from a thing perceived to another, or to different shapes or modes of existence assumed by the same thing. Maybe the thought has to fight with perception only in these respects. It has to reestablish the firmness of approaching the reality, easily disclaimed by the free exercise of perception. Otherwise, the perception is the closest way to the world, or at least was so for the early Greek philosophers.
Aristotle sees two reasons for which perception comes to be confounded with thought and understanding: by its powers of judging (krinein) and recognizing (gnorizein) some of realities (ton onton). We may ignore Aristotle’s suggestion that those realities are the sensibilia, because of its idiosyncratic character. It is worthy to keep on the idea that perception, understanding, and thought are all forms by which human beings dominate or judge the things. It would be worthy to wonder further which of the three processes dominates the realities in the most forceful manner. Because a coercive manner narrows the possibility of knowing the realities. Contrary to Aristotle’s purposes, thought seems the best candidate for being the harsh oppressor and conqueror of realities.
Meanwhile, the perception seems as the best one in being familiar with realities, recognizing or notice (all senses of gnorizein) them, since it is always in the midst of them. Firstly, thought or understanding have to be detached from reality in order to be conceived as different from it and only afterward thought or understanding can attempt to recognize the real things left away.
Moreover, while perception is closest to the man as a body that step in the middle of things, enduring their action and conquering them, the thought and understanding need to place the man in an unaffected place and often such a place is called soul.