In his graphomaniacal muddle he concocted certain theories, which represent so many fits of æsthetic delirium. The most important of these are the dogmas of the _leit-motif_ and of the unending melody. Everyone now undoubtedly knows what Wagner understood by the former. The expression has passed into all civilized languages. The _leit-motif_, in which the threshed-out discarded ‘programme music’ was bound logically to culminate, is a sequence of tones supposed to express a definite conception, and appears in the orchestration whenever the composer intends to recall to the auditor the corresponding conception. By the _leit-motif_ Wagner transforms music into dry speech. The orchestration, leaping from _leit-motif_ to _leit-motif_, no longer embodies general emotions, but claims to appeal to memory and to reason, and communicate sharply defined presentations. Wagner combines a few notes into a musical figure, as a rule not even distinct or original, and makes this arrangement with the auditor:--‘This figure signifies a combat, that a dragon, a third a sword,’ etc. If the auditor does not agree to the stipulation, the _leit-motifs_ lose all significance, for they possess in themselves nothing which compels us to grasp the meaning arbitrarily lent them; and they cannot have anything of this kind in them, because the imitative powers of music are by its nature limited to purely acoustical phenomena, or at most to those optical phenomena ordinarily accompanied by acoustical phenomena. By imitating thunder, music can express the notion of a thunderstorm; by the imitation of the tones of a bugle, it can call up that of an army in such a way that the listener can hardly have a doubt as to the significance of the corresponding sequences of tones. On the other hand, it is absolutely denied to music, with the means at its disposal, to produce an unequivocal embodiment of the visible and tangible world, let alone that of abstract thought. Hence the _leit-motifs_ are at best cold symbols, resembling written characters, which in themselves say nothing, and convey to the initiated and the learned alone the given import of a presentation.