Münsterberg’s fourth _Heft_ begins with studies in association. If _a_ and _b_ have been independently associated with _m_, can _a_ call up _b_ without the appearance in consciousness of _m_? The affirmative answer of common experience was confirmed by Scripture’s experiments. Associating five Japanese symbols with two series of five German words, he found that a word of one series tended (without conscious recollection of the Japanese symbol) to revive the particular word in the other series that had been associated with the same symbol. Münsterberg, after repeating and varying the experiment in a number of fields, denies that any such relation can be observed. He may very well be right on the question of facts. It is _a priori_ improbable that a transitory and arbitrary association of a meaningless symbol could modify appreciably the independent and accidental associative attractions of familiar words and presentations. The philosophic interpretation is another question. For our real knowledge it is a matter of indifference whether we fill out “missing links” with “_dunkel bewusst_,” “_unbewusst_,” or “cerebral processes that have no psychical correlates.” And yet how much of contemporary psychologising is a logomachy raging around just this question. Münsterberg’s second series of experiments show clearly the part played by such missing links in perception. A word is called out just before a complicated picture is exhibited to the subject. He will usually perceive first in the picture some object naturally associated with the word, even though the word has aroused no conscious associations. Similarly (III) a hastily seen misprinted word will be interpreted variously according to the associations of another word called out to the subject in advance. Another series of experiments has for result that even the most commonly associated word-couples, as table and chair, have no fixed, unconditional associative attraction for each other in the same or in different minds, but that the unit of attraction is the “associative constellation.” This is only common sense, and artificial experiments will never reveal anything in this field that we cannot learn quite as well in the class room. “Table” will suggest “logarithm” if the boy is fresh from the class in trigonometry.