The fifteenth yogic sutra speaks in detail about sequence and advancing in a structured process (krama). And, in this process, if a sadhaka progresses sequentially towards change, he is sure to give rise to alterations in consciousness. Patanjali explains it here very vividly through the example of clay and pot. By adopting a specific sequence of methods one shape a lump of clay into an earthenware. Similarly, in yoga also oen has to follow by a certain chain of processes. True consciousness and tranquility can be attained through a logical sequence of spirituality.

Krama going, proceeding, advancing, regular course, method, order of sequence, succession
anyatvam different, distinct
parinama change, transformation, effect
anyatve different, distinct, variant
hetuh cause, reason

Successive sequential changes bring about the distinctive changes in the consciousness.

Differences in changes in consciousness are caused by the changing order of sequences in the method of practice.

According to the sequence of practice, distinct transformations take place. The earthenware pot instance and look at the clay dust as the first principle of evolution, will help one understand the property (dharma) contained in it, the lump of pliable clay which embodies the qualitative mark (laksana), and the jar which culminates the process and which represents the evolved state (avastha). Only by following a certain sequence of actions can one turn earth into pottery. This is harmonious and organic growth.

In yogic practice a regular sequence must also be followed. The sadkaka first acquires restraint in consciousness (nirodha parinama) in order to experience tranquillity (samadhi parinama). Then he proceeds towards the `one without a second`, the seer (ekagrata parinama). Only then does he become a fulfilled yogi (krtarthan) (1.18, 19, and iv.32).

Though consciousness may be considered partially to exist outside time, the work needed to transform that consciousness definitely exists inside the framework of time. It may well be that there is an evolutionary `tilt` to the cosmos by which all things incline to evolve for the better in the long run. But one cannot count on that, and so some amount of individual effort is necessary, especially as the world itself, the only known theatre of action for this evolutionary drama, is now in danger from man`s excesses of pollution, greed and war. Such was not the case in Patanjali`s times, yet he saw fit to furnish the future with an exact evolutionary map, so that one`s advance might be orderly and expeditious.

There is a logic to the involutionary spiritual journey, just as there is in the growth of a plant from seed, to stem, to bud, to flower, to fruit. The original, pure consciousness which one traces through Patanjali`s method is the seed of transformation in oneself. One`s own self is the maker of one`s own spiritual destiny.

The importance of structure and sequence can be shown in the instance of language-learning.

If one starts out to learn a language without structured tuition, one may or may not learn it. It is a `hit or miss` process. But if one seeks to learn in a structured way, there is a definite order of procedure. One starts with the present tense of the verbs `to be` and `to have` and certain basic nouns and prepositions. To start with complex grammatical forms would be idiotic and self-defeating. The structure of evolution and progress in all things has its own inner logic and harmony. This is sequence, or krama.