Secret Means, Book XIV of Arthashastra, mainly talks of the secret efforts of the conqueror to save his kingdom from the enemy. It includes methods like means to injure an enemy; wonderful and delusive contrivances and remedies against the injuries of one's own army.
Secret Means makes a mention of those secret ways in which one could injure one's enemy. In this Kautilya says poison should be administered in the diet of those who are wicked in nature; in order to maintain the caste structure the untouchables or as he calls the 'Mlechchas' can be used in disguise and placed in different countries with different professions. Moreover the spies lying in wait or who are living as inmate in the same house are free to use weapons on certain occasions; the spies who work as nightwalker 'ratrichari", and those as fire keepers or 'agnijivj' can set fire to the enemies. Also Kautilya suggests some more methods to destroy the cattle as well by poisoning them with powder and so on. With a handful of methods formally mentioned in Arthashastra the author then shifts to the other part of secret means when he talks of wonderful and dilutive contrivances.
Secret Means regarding contrivances states a number of combination of elements which will help one to fast for almost a month. These elements will help to poison the enemy slowly and gradually the main intension being spread new instances of fear within the enemy area. This time instead of iron weapons the author resolves to use of chemical reaction by burning animals and animal products to create new series of poisons from animal products. The author then resolves to the method of medicines as well as mantras to bring an end of an enemy.
The book in its next chapter on medicines and mantra explains scientific methods to produce drugs from animal products. It provides a detailed description of the procedure to produce such medicines. Kautilya mentions eight kinds of contrivances causing invisibility with the use of these medicines. The uses of mantras are the next method included in secret means. Kuatilya believed that by the use of mantras, drugs and other magical powers one should protect ones' own people. For this reason he highlights different situations when mantras can be used for the protection of the kith and kin.
Overall Secret Means do include all methods which work besides the regular warfare which possessed great importance at a time when the society was closely covered with black magic and orthodoxy.
