Thus, then, criticisms like this of Mr. Martineau, often recurring in one shape or other, and now again made by Mr. Harrison, do not show the invalidity of my argument, but once more show the imbecility of human intelligence when brought to bear on the ultimate question. Phenomenon without noumenon is unthinkable; and yet noumenon can not be thought of in the true sense of thinking. We are at once obliged to be conscious of a reality behind appearance, and yet can neither bring this consciousness of reality into any shape, nor can bring into any shape its connection with appearance. The forms of our thought, molded on experience of phenomena, as well as the connotations of our words formed to express the relations of phenomena, involve us in contradictions when we try to think of that which is beyond phenomena; and yet the existence of that which is beyond phenomena is a necessary datum alike of our thoughts and our words. We have no choice but to accept a formless consciousness of the inscrutable. Some definitions must now be given. The word "phenomenon" has become naturalized in our English tongue. Derived as a noun from the Greek verb Φαίνομαι, _to appear_, it means anything visible; whatever is presented to the eye by observation or experiment, or what is discovered to exist; as the phenomena of the natural world, the phenomena of the heavenly bodies, of terrestrial substances, the phenomena of heat and color.[95] In this application the word denotes what appears to us, or what we discover by our senses. It is also used, in the plural, more loosely, to denote occurrences or things which we observe to happen; as when, speaking of physical occurrences, we mean physical facts the happening of which we observe. Moral phenomena, on the other hand, are the appearances exhibited by the action of mind.