Searching text

[Heime]

I need to search for phrases like 'others contend' within a buffer, even
when they span across multiple lines. What steps should I take to
achieve this with an elisp function ? 

For example, consider the following text where the phrase 'sees the human 
mind' is split between two lines, yet I need to match it in its entirety.

Theories of how the mind/brain works have been dominated
for centuries by two opposing views. One, rationalism, sees the
human mind as coming into this world more or less fully formed -
preprogrammed, in modern terms. The other, empiricism, sees the
mind of the newborn as largely unstructured, a blank slate.