Eurystheus bids Hercules destroy the Hydra of Lerna, the offspring of Echidna and Typhon, which lived in a forest and marsh near Argos, through which flowed the stream Lerna. This water-serpent had many heads, the middle one of which was immortal. It was poisonous even to its breath.
Hercules attacked it with his arrows and club, but without success, for when one head was destroyed, two others sprang up in its place.
With the assistance of his friend and charioteer, Iolaus, Hercules burnt the root of each head with a hot iron, which prevented further heads from appearing. He then buried the immortal head under a large rock and dipped the arrows in the gall of the Hydra, which had the effect of rendering the wounds they inflicted fatal.
While engaged in this labour, Hera sent a monstrous sea crab to bite the foot of Hercules, but he quickly despatched it, and the crab was said to have been placed in the Constellation Cancer.
Hydra means “moist”, “wet”. It is connected with the principle of Life, of which water is the symbol. But all the offspring of Echidna and Typhon are abnormalities, and thus the snake Hydra, dwelling in the swamp of Lerna, represents degenerate life, which has become corrupt and poisonous in its influence. It is also connected with the insidious and hideous evils of the waters of psychism. Although degraded it is still potent and cannot be exterminated. In fact the more it is opposed by force, the stronger it becomes, this being signified by the immortal head and the appearance of two more heads when one is destroyed. This mythos emphasizes the truth that to fight evil tends to animate and increase it rather than destroy it. Evil is to be transformed into good.
Argos means “white”, “shining”, “bright”; it denotes the pure origin of life.
Iolaus signifies that which is swift in movement, and may be compared with the intuition or the operation of the higher mind of Hercules.
Cancer – “The Crab”, the Zodiacal Sign of Vivific Life. Some inverted Cancerian aspects to be overcome are bitterness, brooding, bigotedness, oversensitivity, anger, whims, bias, touchiness, all grasping and separating tendencies, and the false sense of independence.
The pure influences of Cancer are such as give tenaciousness, receptiveness, patience, sympathy, retentiveness, and self-reliance.
The task of Hercules in this labour may be described as that of overcoming the sense of separateness and all influences which tend to alienate the individual Soul from conscious communion with the life of the universal Soul.
The life manifested by all beings is one in its pure universality, but through the diversity of activity of all creatures it becomes particularized, as it were, and, through inordinations, this pure life is contaminated, so that it poisons all that comes within its sphere of contact.
Degraded life also manifests as the lower desires, bad habits and evil broodings. To seek to kill off or suppress these is usually disastrous, for they feed upon all energies which are directed towards them. Hence the arrows and club (the higher emotions) of Hercules are impotent against the Hydra. But all lower desires and aspects of life may be changed by the fiery spiritual mind (the charioteer, Iolaus and the hot iron), and thus the evil is overcome and the principle of life (immortal head) is again planted in the realm of Spirit (large rock), and Hercules bears away some of its potency (the Hydra’s gall) to assist him in his subsequent encounters in the mundane regions.