The Manifesto for Agile Software Development, also known as "The Agile Manifesto," says:

We are uncovering better ways of developing software
by doing it and helping others do it.
Through this work we have come to value:

Individuals and interactions over processes and tools

Working software over comprehensive documentation

Customer collaboration over contract negotiation

Responding to change over following a plan

That is, while there is value in the items on the right,
we value the items on the left more.

The key relationship expressed by the repeated word "over" is ranking. We compare pairs of items and rank one higher than the other. The summarizing statement that "we value the items on the left more" goes beyond this ranking and sorts all of the items into two buckets. The items on the left are the primary values of agile software development, and the items on the right are secondary values.

Sorting values is a fundamental way in which a community defines itself. As important as this sorting is, I see an even stronger, richer relationship among these values: secondary values in service to primary values. We value the items on the right to the extent that they serve the items on the left.

For example, we value following a plan to the extent that following the plan serves individuals and interactions, helps the project collaborate with its customers, and helps the project respond to change. In order for us to value following a plan, we first want to see how it serves either our identified primary values or some deeper, more fundamental values that transcend The Agile Manifesto.

Trouble starts when projects treat the secondary values of documentation, contracts, processes and tools, and following plans not merely as potential means to achieving deeper values, but as ends in themselves.