The Heart of Virtue, also known as tIq ghob in the ancient Klingon tongue, was a term used as the name for the trefoil symbol of the Klingon Empire. Its roots dated back to an archaic weapon that was favored by Kahless the Unforgettable who later used it as the symbol for his House whereupon he gave it as a unifying image for the Klingon Empire. Furthermore, it was stated that any warrior deficient in one aspect of the Heart of Virtue was doomed to failure.
It was said that the weapon Kahless used was noted for its unequal balance though others disagreed and instead claimed that each of the equal blades represented the different virtues of the Klingon race. These were honor, loyalty and the last was duty with each being in perfect balance with one another. The first of these virtues was duty with it being the beginning and the end of the warriors path due to the fact that without it, a warrior became the victim of vain, glory as well as reckless self interest. A true warrior was stated to not tolerate such vices in either himself or in his comrades. The longest blade in the symbol of the teekn googk was honor which encompassed truth, courage as well as forthrightness. It served as the illuminating difference between a true warrior and an armed savage with its light guiding those that journeyed down the warrior's path. The final blade was attributed to loyalty where all Klingons found glory when one found it that bound them all in a common path.
In the 23rd century, during the training of the Elite Command Academy recruits, General Chang who served as the head instructor taught his students the teachings behind the Heart of Virtue. (TOS video game: Klingon Academy)