Association and comparison, however, as has been pointed out in former essays of this series, are in all cases very closely allied, and sometimes are practically inseparable. Association is based upon suggested likeness in the underlying principle exemplified in two things which are apparently different. Comparison is based upon apparent likeness in the things themselves. Whether, as a fact, we connect them by way of association or of comparison, depends partly upon our point of view, and partly upon the degree of external similarity between them. Sometimes we associate things that are different in specific details, because they are connected with some identical general effect. Thus we associate the moon and the stars, because both are connected with the general effect of the night-time; or hens and turkeys, because both are connected with the general effect of a barn-yard. Yet while this is true, observe also that, in case we be thinking of the heavenly bodies, we can also compare the moon and stars, because, from that point of view, we can find many regards in which in specific details the two are alike, and so, in case we be thinking of fowls, we can compare hens and turkeys. Again, in case a Greek column supporting a heavy entablature be perceived to be like a Gothic column supporting a heavy arch, in one regard alone, namely, in being large in size, then we can say that the one column suggests the other by way of association. But in case the Greek column be perceived to be like another Greek column in most regards or in many regards, then we can say that the one definitely recalls the other by way of comparison. Moreover, in case we have learned that the Greek column is large in order to hold up a heavy weight, then we can infer that the Gothic column is large in order to do the same thing; and we may say that the latter, by way of association, represents the same general idea, or conception, of strength in support which we have originally derived from the former. But if the latter column as well as the former be Greek, that is, if both columns manifest the same details of appearance, then we may say that the latter not only represents the same idea or conception of strength in support as does the former, but that it does this by way of comparison as well as of association.