This essay tries to explain in detail the reasons for the preference of one reading of the 6th verse of introduction of Shahnameh which is about "praise of wisdom" over other readings. In order to achieve this goal, first, expressions like imprudent (kamkherad), unwise, and wise are explained as they are necessary for explaining the expression "dark wisdom"; second, the essay explains the concepts "dark wisdom" and "enlightened soul", and makes it clear that if some other verses of Shahnameh talk about enlightedness of soul, wisdom is also mentioned as soul. It also shows that according to the mental atmosphere of Shahnameh companionship of "dark wisdom" with "enlightened soul" is not possible. The reason is that, on the one hand, knowledge and intelligence are introduced as the causes of enlightedness of wisdom and soul and, on the other hand, wisdom causes soul to benefit from knowledge. Thus enlightening knowledge cannot just enlighten soul but not wisdom, which is the medium of soul`s luminosity and brightness.At the same time, in Shahnameh happiness and soul enlightedness are always together. It means that, according to this work, unhappiness cannot be in fellowship with soul enlightedness. So the reading in which the word "mard" is pronounced as /mard/ and not /marde/ is preferred, as this way of reading conveys that when wisdom is dark, man can neither have enlightened soul nor be happy.