Sri Aurobindo translates Chapter 1, Section 2, Verse 7 of the Mundaka Upanishad as follows: “But frail are the ships of sacrifice, frail these forms of sacrifice, all the eighteen of them, in which are declared the lower works; fools are they who hail them as the highest good and they come yet again to this world of age and death.”
Some commentators go into great descriptions of the external sacrifices, their specific forms and specific applications. Others describe the esoteric and symbolic meaning of this verse. As we are focused on the spiritual development potential described by the Upanishad, we will briefly discuss the symbolic aspect. In this view, the physical body, with its vital and mental capacities developed, represent the “ships of sacrifice” that the soul utilizes to achieve realisation. Sankhya recognizes 24 principles that make up the creation, and 18 of those represent the operations of body, life and mind in the physical world, with 5 elements, 5 senses of perception, 5 senses of action, mind, ego and the reasoning intellect. Esoteric commentators refer to these 18 as the “ships of sacrifice” by which we traverse the world of life as souls embodied in the mortal existence. The focus and activity of these “ships of sacrifice” are the province of the lower knowledge as previously defined. The lower knowledge does not escape from the chain of action, cause and effect, and therefore subjects the individual to birth, growth, illness, suffering and death, along the lines that Buddha described so lucidly. The goal of this Upanishad is to differentiate this lower knowledge from the higher knowledge of the Immutable which takes the soul beyond the limitations and suffering of the world and its activities. Those who therefore concentrate on the forms of sacrifice and the inner sense of the sacrifice within the limits of body, life and mind, find that their results are limited and they do not achieve the higher knowledge through these actions.
Sri Aurobindo has pointed out that the symbolic meaning of the sacrifice is the true inner sense. The development of what the Upanishad calls the lower knowledge is however not entirely sterile and self-defeating, when one considers both the preparation of the being that is involved to achieve the realisation and the need for perfected instruments of action to carry out the significance of the manifested universe rather than simply escape from it by “cutting the knot” of the riddle of existence.
Sri Aurobindo, The Upanishads, Mundaka Upanishad, pp. 193-210