This parallelism between feeling and attention is expressed in the word _interest_. We are interested in those things which conform to our habits of thinking. Because of this conformity they are useful to us at the present moment of our life, and therefore pleasant. Because of this conformity with our habits they become vividly conscious--they are attended to. What is unrelated to our habits of thinking is not useful to us at the moment and is therefore indifferent; and being unrelated, it attracts no attention. Everybody knows how readily the average member of a political party assents to the assertions made by the party leader, how readily the adherent of a religious faith accepts instances proving its correctness, how he unintentionally ignores anything which he cannot accept without opposition or discomfort. Another factor determining attention is the relation of a new impression to the thoughts occupying the mind at the moment when the impression was made. That which is conscious prepares the path over which everything related may enter. Ordinarily the ticking of a clock remains unnoticed. But let the person think of the clock, or of time, and the next tick is clearly perceived. In order to notice a weak tone in a complicated chord, or a melody in polyphonic music, it is well to hear the tone or the melody first in isolation and try to keep it in mind until the chord or the music is played. A slight difference in the color of two leaves remains unnoticed; but if we are thinking of a color difference just before the leaves are shown to us, it becomes at once vivid in our consciousness. The puzzle pictures common in certain popular magazines would never convey the intended meaning to us, if we were not invited by the text to think of various things which they might represent. If we know beforehand in what order a lecturer will present his arguments to us, we can pay attention to the lecture much more easily and understand it better.