That Plato, and Aristotle in somewhat different fashion, and Plotinus and Marcus Aurelius and Saint Thomas Aquinas, and Spinoza and Hegel all taught that Ultimate Reality is either perfectly Ideal and Rational in nature, or else has absolute ideality and rationality as its necessary attribute, are facts well known to the student of philosophy. They need no exposition here. But it is worth pointing out that these great systematic philosophies defined perfect Ideality in conceptions that express the opposite of those things which make life unsatisfactory and troublesome. What is the chief source of the complaint of poet and moralist with the goods, the values and satisfactions of experience? Rarely is the complaint that such things do not exist; it is that although existing they are momentary, transient, fleeting. They do not stay; at worst they come only to annoy and tease with their hurried and disappearing taste of what might be; at best they come only to inspire and instruct with a passing hint of truer reality. This commonplace of the poet and moralist as to the impermanence not only of sensuous enjoyment, but of fame and civic achievements was profoundly reflected upon by philosophers, especially by Plato and Aristotle. The results of their thinking have been wrought into the very fabric of western ideas. Time, change, movement are signs that what the Greeks called Non-Being somehow infect true Being. The phraseology is now strange, but many a modern who ridicules the conception of Non-Being repeats the same thought under the name of the Finite or Imperfect. Wherever there is change, there is instability, and instability is proof of something the matter, of absence, deficiency, incompleteness. These are the ideas common to the connection between change, becoming and perishing, and Non-Being, finitude and imperfection. Hence complete and true Reality must be changeless, unalterable, so full of Being that it always and forever maintains itself in fixed rest and repose. As Bradley, the most dialectially ingenious Absolutist of our own day, expresses the doctrine "Nothing that is perfectly real moves." And while Plato took, comparatively speaking, a pessimistic view of change as mere lapse and Aristotle a complacent view of it as tendency to realization, yet Aristotle doubted no more than Plato that the fully realized reality, the divine and ultimate, is changeless. Though it is called Activity or Energy, the Activity knew no change, the energy did nothing. It was the activity of an army forever marking time and never going anywhere.