We can come across the idea of the mean in practically all the branches of Aristotle's doctrine, from ontology and metaphysics to ethics and politics. Aristotle argues that one can detect the mean “in everything continuous and divisible” if “there is excess and deficiency.” And the basis of this continuity is a motion, “for motion is continuous and action is motion” (Eud. Eth II.3.1220b 21-35). In other words, the mean is characteristic of something continuous, existing in the form of arithmetical progression (from deficiency to excess), as well (63) as of something dynamic, changeable and complex. In ethics, it is a virtue; in a syllogism — a middle term; in a state — a middle class; in time — a “now”; in man — a soul. But for every field of human activity mentioned, its mean is the only static and not developing point — a point of stable equilibrium in balancing between “excess” and “deficiency.”

The intricacy of this term (the mean) is deepened by some symptomatic inconsistency between the principles of the discourse proclaimed by Aristotle himself and the real foundation of his philosophy. He repeatedly affirmed the principle of the excluded middle and the logical impossibility for something having contrary characteristics (for instance, Metaphysics 1011b 20). However, in his own reasoning about the Mind (Nous), the knowing subject and its object become one autonomous self-subsisting “existent,” “what a thing is to be per se” (to on en einai), “final good” (to ariston), “actuality” (entelechia), “first mover” (to proton kinoyn) which is itself unmovable. All these notions presuppose a kind of closure, coincidence or concurrence between the contraries — a beginning (arche), or a cause (aitia), is at the same time an end, or a goal (telos). The latter is not only a result, a final moment of any development, it is initially present from the very beginning, or even before the beginning of things and processes. Thus, a goal, constituting a limit, presents itself both as the beginning and as the final cause and substance.¹⁾ In other words, there is a hidden identity beneath the contraries.

(64) The notion of the mean here comes to the fore — it is in the middle, that the beginning and the end, the cause and the goal come together. That is why “… in all our inquiries we are asking either whether there is a 'middle' or what the 'middle' is: for the 'middle' here is precisely the cause, and it is the cause that we seek in all our inquiries” (Anal Post. 90a 10, tr. by G.R.G. Mure). According to J. van der Meulen, Aristotle's “mean, when it comes to the limit of penetration into a true nature of things, is the Mind in its purest form.”²⁾

Thus the mean is a structural and ontological notion — a kind of perfect, completely accomplished actual state (entelechia) through which “breathes” the Absolute and which, in its most perfect form, is the Absolute itself (Nous, Theos). The analysis of the ethical mean must be firmly based on these metaphysical principles. (2007, p. 62-64)