In order that human life should have vigour, it is necessary for the 
instinctive impulses to be strong and direct; but in order that human 
life should be good, these impulses must be dominated and controlled by 
desires less personal and ruthless, less liable to lead to conflict than 
those that are inspired by instinct alone.  Something impersonal and 
universal is needed over and above what springs out of the principle of 
individual growth.  It is this that is given by the life of the spirit.

Patriotism affords an example of the kind of control which is needed.  
Patriotism is compounded out of a number of instinctive feelings and 
impulses: love of home, love of those whose ways and outlook resemble 
our own, the impulse to co-operation in a group, the sense of pride in 
the achievements of one's group.  All these impulses and desires, like 
everything belonging to the life of instinct, are personal, in the sense 
that the feelings and actions which they inspire towards others are 
determined by the relation of those others to ourselves, not by what 
those others are intrinsically.  All these impulses and desires unite to 
produce a love of a man's own country which is more deeply implanted in 
the fibre of his being, and more closely united to his vital force, than 
any love not rooted in instinct.  But if spirit does not enter in to 
generalize love of country, the exclusiveness of instinctive love makes 
it a source of hatred of other countries.  What spirit can effect is to 
make us realize that other countries equally are worthy of love, that 
the vital warmth which makes us love our own country reveals to us that 
it deserves to be loved, and that only the poverty of our own nature 
prevents us from loving all countries as we love our own.  In this way 
instinctive love can be extended in imagination, and a sense of the 
value of all mankind can grow up, which is more living and intense than 
any that is possible to those whose instinctive love is weak.  Mind can 
only show us that it is irrational to love our own country best; it can 
weaken patriotism, but cannot strengthen the love of all mankind.  
Spirit alone can do this, by extending and universalizing the love that 
is born of instinct.  And in doing this it checks and purifies whatever 
is insistent or ruthless or oppressively personal in the life of 
instinct.

....

Both patriotism and love of man and woman, when they are merely 
instinctive, have the same defects: their exclusions, their enclosing 
walls, their indifference or hostility to the outside world.

....

Background:

At the time, Russell was interested in creating a "new religion" that 
promoted life, not for the sake of life itself, but some "higher" goal 
(he lists God, truth, or beauty).  Hence the references to Spirit.  
Russell described himself as an agnostic, though his definition more 
closely matches what we would call atheist today.